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XAML Animated Headered TextBox Style (Part 2)

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By Fons Sonnemans, 6-3-2017

Last week I wrote a blog item about the XAML Animated Headered TextBox Style. I got a lot of reactions on Twitter. Pieter Otten challenged me into adjusting my solution to make it conform the Material Design guidelines. In Android the header (Label) of the TextBox (Text Field) animates on Focus not when you enter a value. I tried to implement this by adjusting my style but that didn't work. I had to introduce an extra behavior to get it to work. See the result in this video.

AnimatedHeaderedTextBoxStyle demo video which works on Focus

MoveHeaderOnFocusBehavior

The MoveHeaderOnFocusBehavior is used to set the Visual States (Empty and NotEmpty) of the associated TextBox when it is loaded, gets the focus, loses the focus or when the text changes. This Behavior was build by subclassing the Behavior<T> class from the Microsoft.Xaml.Behaviors.Uwp.Managed NuGet package.

public class MoveHeaderOnFocusBehavior : Behavior<TextBox> {

    private bool _hasFocus;

    private void AssociatedObject_GotFocus(object sender, Windows.UI.Xaml.RoutedEventArgs e) {
        _hasFocus = true;
        UpdateState(true);
    }

    private void AssociatedObject_Loaded(object sender, RoutedEventArgs e) {
        UpdateState(false);
        this.AssociatedObject.Loaded -= this.AssociatedObject_Loaded;
    }

    private void AssociatedObject_LostFocus(object sender, Windows.UI.Xaml.RoutedEventArgs e) {
        _hasFocus = false;
        UpdateState(true);
    }

    private void AssociatedObject_TextChanged(object sender, TextChangedEventArgs e) {
        UpdateState(false);
    }

    protected override void OnAttached() {
        base.OnAttached();
        this.AssociatedObject.Loaded += this.AssociatedObject_Loaded;
        this.AssociatedObject.GotFocus += this.AssociatedObject_GotFocus;
        this.AssociatedObject.LostFocus += this.AssociatedObject_LostFocus;
        this.AssociatedObject.TextChanged += this.AssociatedObject_TextChanged;
    }

    protected override void OnDetaching() {
        base.OnDetaching();
        this.AssociatedObject.GotFocus -= this.AssociatedObject_GotFocus;
        this.AssociatedObject.LostFocus -= this.AssociatedObject_LostFocus;
        this.AssociatedObject.TextChanged -= this.AssociatedObject_TextChanged;
    }


    private void UpdateState(bool animate) {
        if (_hasFocus || !string.IsNullOrEmpty(this.AssociatedObject.Text)) {
            VisualStateManager.GoToState(this.AssociatedObject, "NotEmpty", animate);
        } else {
            VisualStateManager.GoToState(this.AssociatedObject, "Empty", animate);
        }
    }

}

 

Usage

I dragged and dropped the MoveHeaderOnFocusBehavior from the Assets window in Blend for Visual Studio to every TextBox of the Style 'AnimatedHeaderedTextBoxStyle'. That's all.

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:App121"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:Interactivity="using:Microsoft.Xaml.Interactivity"
      x:Class="App121.MainPage"
      mc:Ignorable="d">

    <StackPanel Width="300"
                Margin="0,0,60,0"
                VerticalAlignment="Top"
                HorizontalAlignment="Center">

        <TextBox Header="Firstname"
                 Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                 IsSpellCheckEnabled="False"
                 InputScope="PersonalFullName">
            <Interactivity:Interaction.Behaviors>
                <local:MoveHeaderOnFocusBehavior />
            </Interactivity:Interaction.Behaviors>
        </TextBox>

        <TextBox Header="Lastname"
                 Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                 IsSpellCheckEnabled="False"
                 Margin="0,8"
                 InputScope="PersonalFullName">
            <Interactivity:Interaction.Behaviors>
                <local:MoveHeaderOnFocusBehavior />
            </Interactivity:Interaction.Behaviors>
        </TextBox>

        <TextBox Header="E-mail"
                 x:Name="textBoxEmail"
                 Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                 IsSpellCheckEnabled="False"
                 Text="fons.sonnemans@reflectionit.nl"
                 InputScope="EmailNameOrAddress">
            <Interactivity:Interaction.Behaviors>
                <local:MoveHeaderOnFocusBehavior />
            </Interactivity:Interaction.Behaviors>
        </TextBox>

        <Button Content="Next"
                Click="Button_Click"
                Margin="0,16,0,0" />

        <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
              Height="640"
              Margin="0,0,-60,0" />
    </StackPanel>
</Page>

 

The code

I have published the updated code on GitHub. I hope you like it.

I also received some Twitter reactions pointing to this great Inspirational TextBox styles for Windows Phone & Store blogpost from Deani Hansen. That solution uses Styling and subclassing the TextBox control. As always there are many solutions for the same problem.

Fons

XAML Animated Headered TextBox Style

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By Fons Sonnemans, 28-2-2017

A while ago I saw a beautiful effect in an Android app which I was using. It had textboxes with a placeholder text. This placeholder text moved to the header when you enter the first character in the textbox. This triggered me to do the same in a Windows 10 XAML app (UWP). This is a video of the result.

AnimatedHeaderedTextBoxStyle demo video

AnimatedHeaderedTextBoxStyle

My solution is quite simple. I created a Style for a TextBox which has an extra StateGroup named 'HeaderStates'. There are two States in this group named Empty and NotEmpty. The HeaderContentPresenter is moved using TranslateX and TranslateY setters to the correct position. The states are triggered using TemplatedParent databinding to the Text property. I have used a converter which returns true or false when the text is empty or not. I have also changed the BorderThickness property of the Style. It now has only a bottom line and is not boxed any more.

<Style x:Key="AnimatedHeaderedTextBoxStyle"
        TargetType="TextBox">
    <Setter Property="MinWidth"
            Value="{ThemeResource TextControlThemeMinWidth}" />
    <Setter Property="MinHeight"
            Value="{ThemeResource TextControlThemeMinHeight}" />
    <Setter Property="Foreground"
            Value="{ThemeResource TextControlForeground}" />
    <Setter Property="Background"
            Value="{ThemeResource TextControlBackground}" />
    <Setter Property="BorderBrush"
            Value="{ThemeResource TextControlBorderBrush}" />
    <Setter Property="SelectionHighlightColor"
            Value="{ThemeResource TextControlSelectionHighlightColor}" />
    <Setter Property="BorderThickness"
            Value="0,0,0,2" />
    <Setter Property="FontFamily"
            Value="{ThemeResource ContentControlThemeFontFamily}" />
    <Setter Property="FontSize"
            Value="{ThemeResource ControlContentThemeFontSize}" />
    <Setter Property="ScrollViewer.HorizontalScrollMode"
            Value="Auto" />
    <Setter Property="ScrollViewer.VerticalScrollMode"
            Value="Auto" />
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility"
            Value="Hidden" />
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility"
            Value="Hidden" />
    <Setter Property="ScrollViewer.IsDeferredScrollingEnabled"
            Value="False" />
    <Setter Property="Padding"
            Value="{ThemeResource TextControlThemePadding}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TextBox">
                <Grid>
                    <Grid.Resources>
                        <Style x:Name="DeleteButtonStyle"
                                TargetType="Button">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="Button">
                                        <Grid x:Name="ButtonLayoutGrid"
                                                BorderBrush="{ThemeResource TextControlButtonBorderBrush}"
                                                BorderThickness="{TemplateBinding BorderThickness}"
                                                Background="{ThemeResource TextControlButtonBackground}">
                                            <VisualStateManager.VisualStateGroups>
                                                <VisualStateGroup x:Name="CommonStates">
                                                    <VisualState x:Name="Normal" />
                                                    <VisualState x:Name="PointerOver">
                                                        <Storyboard>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
                                                                                            Storyboard.TargetName="ButtonLayoutGrid">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonBackgroundPointerOver}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
                                                                                            Storyboard.TargetName="ButtonLayoutGrid">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonBorderBrushPointerOver}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                                            Storyboard.TargetName="GlyphElement">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonForegroundPointerOver}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                        </Storyboard>
                                                    </VisualState>
                                                    <VisualState x:Name="Pressed">
                                                        <Storyboard>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
                                                                                            Storyboard.TargetName="ButtonLayoutGrid">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonBackgroundPressed}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
                                                                                            Storyboard.TargetName="ButtonLayoutGrid">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonBorderBrushPressed}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                                            Storyboard.TargetName="GlyphElement">
                                                                <DiscreteObjectKeyFrame KeyTime="0"
                                                                                        Value="{ThemeResource TextControlButtonForegroundPressed}" />
                                                            </ObjectAnimationUsingKeyFrames>
                                                        </Storyboard>
                                                    </VisualState>
                                                    <VisualState x:Name="Disabled">
                                                        <Storyboard>
                                                            <DoubleAnimation Duration="0"
                                                                                To="0"
                                                                                Storyboard.TargetProperty="Opacity"
                                                                                Storyboard.TargetName="ButtonLayoutGrid" />
                                                        </Storyboard>
                                                    </VisualState>
                                                </VisualStateGroup>
                                            </VisualStateManager.VisualStateGroups>
                                            <TextBlock x:Name="GlyphElement"
                                                        AutomationProperties.AccessibilityView="Raw"
                                                        Foreground="{ThemeResource TextControlButtonForeground}"
                                                        FontStyle="Normal"
                                                        FontSize="12"
                                                        FontFamily="{ThemeResource SymbolThemeFontFamily}"
                                                        HorizontalAlignment="Center"
                                                        Text="&#xE10A;"
                                                        VerticalAlignment="Center" />
                                        </Grid>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </Grid.Resources>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="HeaderContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlHeaderForegroundDisabled}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBackgroundDisabled}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBorderBrushDisabled}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlForegroundDisabled}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlPlaceholderForegroundDisabled}" />
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Normal" />
                            <VisualState x:Name="PointerOver">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBorderBrushPointerOver}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBackgroundPointerOver}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlPlaceholderForegroundPointerOver}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlForegroundPointerOver}" />
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Focused">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlPlaceholderForegroundFocused}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBackgroundFocused}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
                                                                    Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlBorderBrushFocused}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
                                                                    Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="{ThemeResource TextControlForegroundFocused}" />
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="RequestedTheme"
                                                                    Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0"
                                                                Value="Light" />
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="ButtonStates">
                            <VisualState x:Name="ButtonVisible">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility"
                                                                    Storyboard.TargetName="DeleteButton">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Visibility>Visible</Visibility>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="ButtonCollapsed" />
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="HeaderStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition GeneratedDuration="0:0:0.35">
                                    <VisualTransition.GeneratedEasingFunction>
                                        <CircleEase EasingMode="EaseInOut" />
                                    </VisualTransition.GeneratedEasingFunction>
                                </VisualTransition>
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="NotEmpty">
                                <VisualState.Setters>
                                    <Setter Target="HeaderContentPresenter.(UIElement.RenderTransform).(CompositeTransform.TranslateY)"
                                            Value="0" />
                                    <Setter Target="HeaderContentPresenter.(UIElement.RenderTransform).(CompositeTransform.TranslateX)"
                                            Value="0" />
                                </VisualState.Setters>
                                <VisualState.StateTriggers>
                                    <StateTrigger IsActive="{Binding Text, Converter={StaticResource IsNotEmptyConverter}, Mode=OneWay, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
                                </VisualState.StateTriggers>
                            </VisualState>
                            <VisualState x:Name="Empty">
                                <VisualState.Setters>
                                    <Setter Target="HeaderContentPresenter.(UIElement.RenderTransform).(CompositeTransform.TranslateY)"
                                            Value="31" />
                                    <Setter Target="HeaderContentPresenter.(UIElement.RenderTransform).(CompositeTransform.TranslateX)"
                                            Value="11" />
                                </VisualState.Setters>
                                <VisualState.StateTriggers>
                                    <StateTrigger IsActive="{Binding Text, Converter={StaticResource IsEmptyConverter}, Mode=OneWay, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
                                </VisualState.StateTriggers>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Border x:Name="BorderElement"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Background="{TemplateBinding Background}"
                            Grid.ColumnSpan="2"
                            Grid.Row="1"
                            Grid.RowSpan="1" />
                    <ContentPresenter x:Name="HeaderContentPresenter"
                                        Grid.ColumnSpan="2"
                                        ContentTemplate="{TemplateBinding HeaderTemplate}"
                                        Content="{TemplateBinding Header}"
                                        Foreground="{ThemeResource TextControlHeaderForeground}"
                                        FontWeight="Normal"
                                        Margin="0,0,0,8"
                                        Grid.Row="0"
                                        Visibility="Collapsed"
                                        x:DeferLoadStrategy="Lazy"
                                        RenderTransformOrigin="0.5,0.5">
                        <ContentPresenter.RenderTransform>
                            <CompositeTransform />
                        </ContentPresenter.RenderTransform>
                    </ContentPresenter>
                    <ScrollViewer x:Name="ContentElement"
                                    AutomationProperties.AccessibilityView="Raw"
                                    HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
                                    HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                                    IsTabStop="False"
                                    IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
                                    IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
                                    IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
                                    Margin="{TemplateBinding BorderThickness}"
                                    Padding="{TemplateBinding Padding}"
                                    Grid.Row="1"
                                    VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                                    VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
                                    ZoomMode="Disabled" />
                    <ContentControl x:Name="PlaceholderTextContentPresenter"
                                    Grid.ColumnSpan="2"
                                    Content="{TemplateBinding PlaceholderText}"
                                    Foreground="{ThemeResource TextControlPlaceholderForeground}"
                                    IsHitTestVisible="False"
                                    IsTabStop="False"
                                    Margin="{TemplateBinding BorderThickness}"
                                    Padding="{TemplateBinding Padding}"
                                    Grid.Row="1" />
                    <Button x:Name="DeleteButton"
                            AutomationProperties.AccessibilityView="Raw"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Grid.Column="1"
                            FontSize="{TemplateBinding FontSize}"
                            IsTabStop="False"
                            Margin="{ThemeResource HelperButtonThemePadding}"
                            MinWidth="34"
                            Grid.Row="1"
                            Style="{StaticResource DeleteButtonStyle}"
                            Visibility="Collapsed"
                            VerticalAlignment="Stretch" />
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

The converter is very simple. It has an extra IsInvertered property to invert a True to a False.

public class EmptyStringToTrueConverter : IValueConverter {
    public bool IsInverted { get; set; }

    public object Convert(object value, Type targetType, object parameter, string language) {
        var txt = (string)value;
        return string.IsNullOrEmpty(txt) ^ IsInverted;
    }

    public object ConvertBack(object value, Type targetType, object parameter, string language) {
        return DependencyProperty.UnsetValue;
    }
}

The converteres are registered using the following XAML.

<local:EmptyStringToTrueConverter x:Key="IsNotEmptyConverter" IsInverted="True" />
<local:EmptyStringToTrueConverter x:Key="IsEmptyConverter" />

Usage

My example page which I used in the video is shown below. All TextBoxes have the Style property set to AnimatedHeaderedTextBoxStyle and off course a Header property. I have set the IsSpellCheckEnable property to False because I don't want spellchecking on names and email addresses.  

<Page x:Class="App121.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:App121"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      mc:Ignorable="d">

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <StackPanel Width="300"
                    Margin="0,12"
                    VerticalAlignment="Top"
                    HorizontalAlignment="Center">

            <TextBox Header="Firstname"
                     Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                     IsSpellCheckEnabled="False"
                     InputScope="PersonalFullName"/>

            <TextBox Header="Lastname"
                     Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                     IsSpellCheckEnabled="False"
                     Margin="0,8"
                     InputScope="PersonalFullName" />

            <TextBox Header="E-mail"
                     Style="{StaticResource AnimatedHeaderedTextBoxStyle}"
                     IsSpellCheckEnabled="False"
                     InputScope="EmailNameOrAddress" />

            <Button Content="Next"
                    Margin="0,16,0,0" />
        </StackPanel>

    </Grid>
</Page>

I have placed the AnimatedHeaderedTextBoxStyle, the registration of the converters and a DeleteButtonStyle into ResourceDictionary named AnimatedHeaderedTextBoxStyle.xaml. The DeleteButtonStyle was generated by Blend when I created the Style by 'Editing a Copy...' of the Template for an existing TextBox.

Edit a Copy

In have registered the ResourceDictionary from the App.xaml which makes it available for in all pages and controls in this application.

<Application
    x:Class="App121.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App121"
    RequestedTheme="Light">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="AnimatedHeaderedTextBoxStyle.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

The easiest way to add this Resource Dictionary as a MergedDictionaries in the App.xaml is to use Blend. Open the Resources Window and right click the App.xaml file. Then select 'Link to Resource Dictionary' and check the AnimatedHeaderedTextBoxStyle.xaml file.

Link to ResourceDictionary

The code

I have published my code on GitHub. I hope you like it.

Fons

XAML Storyboard.IsPlaying Attached Property

0 Comments
By Fons Sonnemans, 24-2-2017

XAML is very powerful. I have blogged about behaviors a lot. They are great but also have limitations. You can only drag them on Controls, not on Storyboards. To "fix" this I came up with a solution using Attached Properties. The designer support isn't as good with Behaviors but who needs that if we have IntelliSense.

IsPlaying Attached Property

I have created a StoryboardServices class which contains the IsPlaying attached property of the type boolean. In the OnIsPlayingChanged() method I Begin() or Resume() the Storyboard if it is set to True, I Pause() it when it is set to False.

using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Media.Animation;

namespace AnimationDemo {
    public class StoryboardServices {

        #region IsPlaying Attached Property

        /// <summary> 
        /// Identifies the IsPlaying attachted property. This enables animation, styling, binding, etc...
        /// </summary>
        public static readonly DependencyProperty IsPlayingProperty =
            DependencyProperty.RegisterAttached("IsPlaying",
                typeof(bool),
                typeof(StoryboardServices),
                new PropertyMetadata(false, OnIsPlayingChanged));

        /// <summary>
        /// IsPlaying changed handler. 
        /// </summary>
        /// <param name="d">FrameworkElement that changed its IsPlaying attached property.</param>
        /// <param name="e">DependencyPropertyChangedEventArgs with the new and old value.</param> 
        private static void OnIsPlayingChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
            var source = d as Storyboard;
            if (source != null) {
                var value = (bool)e.NewValue;
                if (value) {
                    if (source.GetCurrentState() == ClockState.Stopped) {
                        source.Begin();
                    } else {
                        source.Resume();
                    }
                } else {
                    source.Pause();
                }
            }
        }

        /// <summary>
        /// Gets the value of the IsPlaying attached property from the specified FrameworkElement.
        /// </summary>
        public static bool GetIsPlaying(DependencyObject obj) {
            return (bool)obj.GetValue(IsPlayingProperty);
        }


        /// <summary>
        /// Sets the value of the IsPlaying attached property to the specified FrameworkElement.
        /// </summary>
        /// <param name="obj">The object on which to set the IsPlaying attached property.</param>
        /// <param name="value">The property value to set.</param>
        public static void SetIsPlaying(DependencyObject obj, bool value) {
            obj.SetValue(IsPlayingProperty, value);
        }

        #endregion IsPlaying Attached Property

    }
}

Example

In this example I have a Storyboard1 which plays when the checkbox on the page is checked. I databound the IsPlaying attached property to the IsChecked property of the checkbox (see line 10). The animation is really simple but you get the idea.

<Page x:Class="AnimationDemo.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:AnimationDemo"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      mc:Ignorable="d">
    <Page.Resources>
        <Storyboard x:Name="Storyboard1"
             local:StoryboardServices.IsPlaying="{Binding IsChecked, ElementName=checkBoxIsAnimated, Mode=OneWay}"
             RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames
                    Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                   Storyboard.TargetName="myBorder">
                <EasingColorKeyFrame KeyTime="0:0:1"
                                     Value="Blue" />
                <EasingColorKeyFrame KeyTime="0:0:2"
                                     Value="Red" />
            </ColorAnimationUsingKeyFrames>
        </Storyboard>
    </Page.Resources>

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="1*" />
            <ColumnDefinition Width="2*" />
            <ColumnDefinition Width="1*" />
        </Grid.ColumnDefinitions>

        <CheckBox x:Name="checkBoxIsAnimated"
                  Content="Animate"
                  IsChecked="True"
                  VerticalAlignment="Top"
                  HorizontalAlignment="Center"
                  Grid.Column="1" />

        <Border x:Name="myBorder"
                Height="100"
                Grid.Column="1"
                Background="Red" />
    </Grid>
</Page>

The code

I have published my code on GitHub. I hope you like it.

Fons

XAML ScrollSelectedItemIntoViewBehavior

0 Comments
By Fons Sonnemans, 12-1-2017

I love C#, XAML and Blend. It is very powerful and lets me create powerful solutions. As a example of it's power I will demonstrate my ScrollSelectedItemIntoViewBehavior. It will let you scroll to a selected item into view of a ListView or GridView without having to write any code.

Demo

The following video (GIF) shows you how you can use it to scroll to the selected product into view of a ListView. This can be done animated or instant.

ScrollSelectedItemIntoViewBehavior Demo

My Solution

My solution is a Behavior which you can apply on any ListView or GridView using Blend for Visual Studio. I have included the Microsoft.Xaml.Behaviors.Uwp.Managed NuGet package to the project. The ScrollSelectedItemIntoViewBehavior class derives from the Behavior<T> class (from the NuGet package) in which T is a ListViewBase. This allows me to use (drop) the behavior on a ListView or GridView. In the OnAttached() and OnDetached() methods I subscribe/unsubscribe to the SelectionChanged event of the AssociatedObject, the ListView or GridView. In the AssociatedObject_SelectionChanged() method the AssociatedObject scrolls to the selected item. For the scrolling I use some code (extension methods) I found on StackOverflow which does the hard work. I only changed some naming of the methods to follow my own code conventions.

public class ScrollSelectedItemIntoViewBehavior : Behavior<ListViewBase> {

    protected override void OnAttached() {
        AssociatedObject.SelectionChanged += AssociatedObject_SelectionChanged;
        base.OnAttached();
    }
    protected override void OnDetaching() {
        AssociatedObject.SelectionChanged -= AssociatedObject_SelectionChanged;
        base.OnDetaching();
    }

    private async void AssociatedObject_SelectionChanged(object sender, 
                                                    SelectionChangedEventArgs e) {
        var item = e.AddedItems.FirstOrDefault();
        if (item != null) {
            if (IsScrollAnimated) {
                await this.AssociatedObject.ScrollToItemAsync(item);
            } else {
                await this.AssociatedObject.ScrollIntoViewAsync(item);
            }
        }
    }

    /// <summary> 
    /// Get or Sets the IsScrollAnimated dependency property.  
    /// </summary> 
    public bool IsScrollAnimated {
        get { return (bool)GetValue(IsScrollAnimatedProperty); }
        set { SetValue(IsScrollAnimatedProperty, value); }
    }

    /// <summary> 
    /// Identifies the IsScrollAnimated dependency property. 
    /// This enables animation, styling, binding, etc...
    /// </summary> 
    public static readonly DependencyProperty IsScrollAnimatedProperty =
        DependencyProperty.Register(nameof(IsScrollAnimated),
                            typeof(bool),
                            typeof(ScrollSelectedItemIntoViewBehavior),
                            new PropertyMetadata(true));
}

 

Using the Behavior

My sample project also contains some SampleData (products) which I used to populate a ListView. I have dragged the ScrollSelectedItemIntoViewBehavior from the Assets panel and dropped it on the ListView. The behavior also contains an IsScrollAnimated dependency property. The ToggleSwitch is databound to this property.

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:App47"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:Interactivity="using:Microsoft.Xaml.Interactivity"
      xmlns:Behaviors="using:App47.Behaviors"
      x:Class="App47.MainPage"
      mc:Ignorable="d">

    <Page.Resources>
        <DataTemplate x:Key="ProductTemplate">
            <Grid Height="80"
                  Margin="0,4">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <Image Source="{Binding ImageUrl}"
                       Height="80"
                       Width="80" />
                <StackPanel Grid.Column="1"
                            Margin="8,0,0,0">
                    <TextBlock Text="{Binding Name}"
                               Style="{StaticResource TitleTextBlockStyle}" />
                    <TextBlock Text="{Binding Price}"
                               Style="{StaticResource CaptionTextBlockStyle}"
                               TextWrapping="NoWrap" />
                </StackPanel>
            </Grid>
        </DataTemplate>
    </Page.Resources>

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
          DataContext="{Binding Source={StaticResource SampleDataSource}}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="380*" />
            <ColumnDefinition Width="1541*" />
        </Grid.ColumnDefinitions>
        <StackPanel>
            <Button Content="First"
                    Click="ButtonFirst_Click"
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Margin="4" />
            <Button Content="Middle"
                    Click="ButtonMiddle_Click"
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Margin="4" />
            <Button Content="Last"
                    Click="ButtonLast_Click"
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Margin="4" />
            <ToggleSwitch Header="IsAnimated"
                          Margin="4"
                          IsOn="{x:Bind myBehavior.IsScrollAnimated, Mode=TwoWay}" />
        </StackPanel>
        <ListView x:Name="listViewProducts"
                  Grid.Column="1"
                  ItemTemplate="{StaticResource ProductTemplate}"
                  ItemsSource="{Binding Products}">
            <Interactivity:Interaction.Behaviors>
                <Behaviors:ScrollSelectedItemIntoViewBehavior x:Name="myBehavior" />
            </Interactivity:Interaction.Behaviors>
        </ListView>
    </Grid>
</Page>

The buttons click eventhandlers only set the SelectedIndex of the ListView. An MVVM solution in which the SelectedIndex is databound to a property of a model would also work.

public sealed partial class MainPage : Page {

    public MainPage() {
        this.InitializeComponent();
    }

    private void ButtonFirst_Click(object sender, RoutedEventArgs e) {
        listViewProducts.SelectedIndex = 0;
    }

    private void ButtonMiddle_Click(object sender, RoutedEventArgs e) {
        listViewProducts.SelectedIndex = (listViewProducts.Items.Count - 1) / 2;
    }

    private void ButtonLast_Click(object sender, RoutedEventArgs e) {
        listViewProducts.SelectedIndex = listViewProducts.Items.Count - 1;

    }
}

The code

I have published my code on GitHub. I hope you like it.

Fons

XAML CalculatorBehavior

0 Comments
By Fons Sonnemans, 1-12-2016

I have been using Adobe software recently and I noticed you could do simple calculations in textboxes. I used it to export Tile Images in different scale sizes. If the 100% scale of an Image is 150 pixels wide you can enter '150 * 1.5'. It will calculate the width of 225 pixels for the 150% scale size. I loved this feature so I tried to implement it also for my own Xaml apps.

The solution is quite simple. I have created a Behavior called CalculatorBehavior. You just use Blend for Visual Studio to drop it on a TextBox control and you are done.

Demo App

The following video shows you how you can use it to do simpel calculations in a TextBox using the CalculatorBehavior.

CalculatorBehavior Demo

My Solution

My Visual Studio solution contains 3 projects: Windows 10 (UWP), Windows 8.1 and WPF. The WPF project has a NuGet reference to Math Expression Evaluator. This project contains the ExpressionEvaluator class which I use for my calculations. There is no WinRT, PCL (Portable Class Library) or .NET Standard implementation for this project which makes it unusable for my Windows (8.1 and 10/UWP) projects. Luckily the project is Open Sources so I added the ExpressionEvaluator class to these projects.

The Windows 10 project uses the XamlBehaviors project using the NuGet package. The Windows 8.1 project uses the 'Behaviors SDK' but that doesn't include a Behavior<T> class. So i added my own implementation for it in my project. The WPF project has a reference to the 'System.Windows.Interactivity' assembly.

CalculatorBehavior

The CalculatorBehavior code is very simple. The class derives from Behavior<TextBox> which makes it droppable on a TextBox. The LostFocus event of the TextBox will trigger the calculation for which I use the ExpressionEvaluator.

using Microsoft.Xaml.Interactivity;
using SimpleExpressionEvaluator;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace CalculatorUwpDemoApp.Behaviors {

    class CalculatorBehavior : Behavior<TextBox> {

        private static readonly ExpressionEvaluator _evaluator = 
            new ExpressionEvaluator();

        protected override void OnAttached() {
            base.OnAttached();
            this.AssociatedObject.LostFocus += Evaluate;
        }

        protected override void OnDetaching() {
            base.OnDetaching();
            this.AssociatedObject.LostFocus -= Evaluate;
        }

        private void Evaluate(object sender, RoutedEventArgs e) {
            try {
                string txt = this.AssociatedObject.Text;
                if (!string.IsNullOrWhiteSpace(txt)) {
                    var result = _evaluator.Evaluate(txt);
                    this.AssociatedObject.Text = result.ToString();
                }
            } catch { }
        }
    }
}

Blend for Visual Studio

Adding the CalculatorBehavior to a TextBox is very easy in Blend for Visual Studio. Select the behavior from the Assets panel and Drag&Drop it on a TextBox. That's all.

Blend Screenshot

The code

I have published my code on GitHub. I hope you like it.

Fons

Windows 10 XAML Tips: AnimatedTextBlock

0 Comments
By Fons Sonnemans, 21-3-2016

For one of my Windows games I created an AnimatedTextBlock control which animates the Text when it changes. This attracks the user attention. In this blog I will explain how I implemented it. The following animated GIF show's you this AnimtatedTextBlock in my sample app. Everytime you tap the button the text is changed from 'Hello' to 'World' and back.

AnimatedTextBlock

The AnimatedTextBlock is an UserControl which contains a TextBlock and a Storyboard. The Storyboard contains a PlaneProjection.RotationX animation which rotates the TextBlock and a TextBlock.Text animation which sets the Text. The Font properties of the TextBlock like FontSize and FontFamily are inherited from the UserControl.

<UserControl x:Class="App91.Views.Controls.AnimatedTextBlock"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             d:DesignHeight="22.667"
             d:DesignWidth="400">
    <UserControl.Resources>
        <Storyboard x:Name="Storyboard1">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(PlaneProjection.RotationX)"
                                           Storyboard.TargetName="textBlockProjection">
                <EasingDoubleKeyFrame KeyTime="0"
                                      Value="0" />
                <EasingDoubleKeyFrame KeyTime="0:0:0.2"
                                      Value="90" />
                <EasingDoubleKeyFrame KeyTime="0:0:0.4"
                                      Value="0" />
            </DoubleAnimationUsingKeyFrames>
            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(TextBlock.Text)"
                                           Storyboard.TargetName="innerTextBlock">
                <DiscreteObjectKeyFrame KeyTime="0:0:0.2"
                                        x:Name="textFrame" />
            </ObjectAnimationUsingKeyFrames>
        </Storyboard>
    </UserControl.Resources>
    <TextBlock x:Name="innerTextBlock"
               TextWrapping="{x:Bind TextWrapping, Mode=OneWay}"
               RenderTransformOrigin="0.5,0.5">
        <TextBlock.Projection>
            <PlaneProjection RotationX="0"
                             x:Name="textBlockProjection" />
        </TextBlock.Projection>
    </TextBlock>
</UserControl>

In the code behind of the UserControl there is a Text dependency property which will allow Styling and DataBinding of this property. The OnTextPropertyChanged method is automatically called when the value of this property changes. In this method the value of the Text animation is set to the new value and the Storyboard is started. The class also contains a TextWrapping dependency property which is used in the XAML code to databind the TextBlock TextWrapping property to using compiled binding. For my solution I only needed this TextWrapping property but you might have to add extra properties like TextAlignment or TextLineBounds.

public sealed partial class AnimatedTextBlock : UserControl {

    public AnimatedTextBlock() {
        this.InitializeComponent();
    }

    public string Text {
        get { return (string)GetValue(TextProperty); }
        set { SetValue(TextProperty, value); }
    }

    public static readonly DependencyProperty TextProperty =
        DependencyProperty.Register(nameof(Text), typeof(string),
            typeof(AnimatedTextBlock),
            new PropertyMetadata(null, OnTextPropertyChanged));

    private static void OnTextPropertyChanged(DependencyObject d,
                            DependencyPropertyChangedEventArgs e) {
        var source = d as AnimatedTextBlock;
        if (source != null) {
            var value = (string)e.NewValue;
            if (e.OldValue != null) {
                source.textFrame.Value = value;
                source.Storyboard1.Begin();
            } else {
                source.innerTextBlock.Text = value;
            }
        }
    }

    public TextWrapping TextWrapping {
        get { return (TextWrapping)GetValue(TextWrappingProperty); }
        set { SetValue(TextWrappingProperty, value); }
    }

    public static readonly DependencyProperty TextWrappingProperty =
        DependencyProperty.Register(nameof(TextWrapping), typeof(TextWrapping),
            typeof(AnimatedTextBlock), new PropertyMetadata(TextWrapping.NoWrap));

}

Sample page

In my sample page I have added a Button and an AnimatedTextBlock control to the root Grid of the Page. The AnimatedTextBlock is named 'atb1' so i can be used in the code behind of the page.

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:App91"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:Controls="using:App91.Views.Controls"
      x:Class="App91.MainPage"
      mc:Ignorable="d">

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        
        <Button Content="Button"
                HorizontalAlignment="Stretch"
                Height="63"
                Margin="55,64,81,0"
                VerticalAlignment="Top"
                Click="Button_Click" />

        <Controls:AnimatedTextBlock x:Name="atb1"
                                    Margin="32,173,58,0"
                                    VerticalAlignment="Top"
                                    Text="Hello"
                                    Foreground="Red"
                                    TextWrapping="Wrap"
                                    FontSize="48" />

    </Grid>
</Page>

The Button has a Click event which toggles the Text of the AnimatedTextBlock Text from Hello to World.

private bool _showHello;

private void Button_Click(object sender, RoutedEventArgs e) {
    atb1.Text = _showHello ? "Hello" : "World";
    _showHello = !_showHello;
}

Closure and download

I hope you can use this blog for your own Windows 10 apps. You can download the sample project below.

Cheers,

Fons

Tags: Apps, XAML, UWP, Windows 10

Developing and Deploying Windows 10 Apps

0 Comments
By Fons Sonnemans, 1-12-2015

26 november heb ik names de StoreApps User Group de onderstaande presentatie gegeven bij iSense in Zwolle. Op veler verzoek kan de de presentatie hieronder bekijken en downloaden.

Developing and Deploying Windows 10 Apps from Fons Sonnemans

TechFriyday videos

0 Comments
By Fons Sonnemans, 26-5-2015

Op de Microsoft TechBlog heeft Microsoft Nederland een reeks van video blogs geplaats onder de noemer Tech Friday. In deze videos interviewed Clemens Schotte (Microsoft Technical Evangelist) specialisten in het vak over verschillende onderwerpen. In twee van deze video's houdt Clemens een interview met Fons Sonnemans.

Mijn eerste Windows App ontwikkelen – TechFriday, aflevering 15

Hoe moet je beginnen en wat heb je nodig om je eerste Windows of Windows Phone app te ontwikkelen? Fons Sonnemans van Reflection IT maakt je wegwijs in Visual Studio bij het bouwen van je eerste app. Je kunt Windows of Windows Phone apps ontwikkelen in verschillende programeertalen, zoals C#, VB, C++ en JavaScript. De visuele opmaaktaal is XAML of HTML, door gebruik te maken van Blend (onderdeel van Visual Studio) kun je eenvoudig schermen ontwerpen met controls en zelfs animaties die je nodig hebt in je app. Je ontwikkelde app kun je gemakkelijk testen op je huidige apparaat, maar ook met de simulator voor bijvoorbeeld een tablet of telefoon.

Mijn app in de Windows Store plaatsen – TechFriday, aflevering 16

Om een app in de Windows Store te kunnen zetten moet je eenmalig een Windows developer account aanmaken. Je hebt dan een developer-licentie. In Visual Studio – waarin je je app ook hebt gebouwd- kun je gemakkelijk je app in de Windows Store plaatsen. Fons is nogmaals bij Microsoft te gast om dit proces door te nemen.

Tags: XAML, Apps

Windows XAML Tips - ResourceDictionary with CodeBehind

0 Comments
By Fons Sonnemans, 17-4-2015

I have created XAML solutions (WPF, Silverlight, Windows Phone, Windows 8) for about 7 years now. This week I learned a new feature which I thought wasn't possible. I learned how you can place DataTemplates with eventhandlers into ResouceDictionaries. I thought this wasn't possible because ResourceDictionaries don't have CodeBehind files to write the eventhandlers in. But I was wrong. You can add a CodeBehind to a ResourceDictionary but you will have to do it manually. This makes it possible to move more DataTemplates and ControlTemplates from Pages and UserControls to ResourceDictionaries which can help to avoid duplicate XAML code.

Demo App

My demo app is a Windows app developed using the MVVM design pattern. It contains a MainPage (view), a MainViewModel (viewmodel) class and a Product (model) class. The MainViewModel has a Products property which is a list of 3 hard coded products. The MainPage has a ListView which ItemsSource is DataBound to the Products property of the MainViewModel. The ItemsTemplate of the ListView is set to the ProductsDataTemplate which is a static resource of the Page. This DataTemplate contains an Image control which has 2 events (PointerEntered and PointerExited). In this example I changed the Opacity of the image when you hover over it using your mouse. It is a silly implementation which could also have been implemented using Behaviors in Blend.

MainPage.xaml

<Page x:Class="ResourceDictionaryWithCodeBehindDemo.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:ResourceDictionaryWithCodeBehindDemo"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:vm="using:ResourceDictionaryWithCodeBehindDemo.ViewModels"
      mc:Ignorable="d">

    <Page.Resources>
        <DataTemplate x:Key="ProductDataTemplate">
            <StackPanel Orientation="Horizontal">
                <Image Source="{Binding ImageUrl}"
                       PointerEntered="Image_PointerEntered"
                       PointerExited="Image_PointerExited"
                       Opacity="0.3"
                       Width="100"
                       Height="100" />
                <StackPanel Margin="20,0">
                    <TextBlock Text="{Binding Name}" 
                               FontSize="30"/>
                    <TextBlock Text="{Binding Price}"
                               FontSize="20" />
                </StackPanel>
            </StackPanel>
        </DataTemplate>
    </Page.Resources>

    <Page.DataContext>
        <vm:MainViewModel />
    </Page.DataContext>

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <ListView Margin="50"
                  ItemsSource="{Binding Products}"
                  ItemTemplate="{StaticResource ProductDataTemplate}">
        </ListView>
    </Grid>
</Page>

The MainPage.xaml.cs file contains the MainPage class with the Image_PointerEntered and Image_PointerExited eventhandlers. They change the Opacity of the Image (sender).

public sealed partial class MainPage : Page {
    public MainPage() {
        this.InitializeComponent();
    }

    private void Image_PointerEntered(object sender, PointerRoutedEventArgs e) {
        var img = sender as Image;
        img.Opacity = 1.0;
    }

    private void Image_PointerExited(object sender, PointerRoutedEventArgs e) {
        var img = sender as Image;
        img.Opacity = 0.3;
    }
}

The MainViewModel.cs file contains the MainViewModel class which has the Products property. The Constructor adds 3 sample products to the List.

using System;
using ResourceDictionaryWithCodeBehindDemo.Models;
using System.Collections.Generic;

namespace ResourceDictionaryWithCodeBehindDemo.ViewModels {
    class MainViewModel {

        public List<Product> Products { get; set; }

        public MainViewModel() {
            this.Products = new List<Product>() {
                new Product { Name = "Computer", Price = 2000},
                new Product { Name = "Car", Price = 34000},
                new Product { Name = "Table", Price = 500},
            };
        }
    }
}

The Product.cs file contains the Product class with the Name, Price and ImageUrl properties.

using System;

namespace ResourceDictionaryWithCodeBehindDemo.Models {
    class Product {

        public string Name { get; set; }
        public double Price { get; set; }

        public string ImageUrl {
            get {
                return "http://lorempixel.com/150/150/technics/" + Name;
            }
        }
    }
}

Add ResourceDictionary

Now you can add a ResourceDictionary to the project. Created a folder Resources in the root of the Project in which you will add the ResourceDictionary file. Create this file in Blend and not in Visual Studio because Blend will add the MergedDictionary code to my App.xaml. I named my file MyDataTemplates.xaml.

Add new Item in Blend

MyDataTemplates.xaml will look like this.

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:ResourceDictionaryWithCodeBehindDemo">
    
</ResourceDictionary>

Blend will also add the ResourceDictionary to the MergedDictionary of your Application in the  App.xaml.

<Application
    x:Class="ResourceDictionaryWithCodeBehindDemo.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:ResourceDictionaryWithCodeBehindDemo">
    
	<Application.Resources>
		<ResourceDictionary>
			<ResourceDictionary.MergedDictionaries>
				<ResourceDictionary Source="Resources/MyDataTemplates.xaml"/>
			</ResourceDictionary.MergedDictionaries>
		</ResourceDictionary>
	</Application.Resources>

</Application>

Add CodeBehind to ResourceDictionary

Now you can create the MyDataTemplates.xaml.cs file in the Resources folder of the project. I do this in Visual Studio and not in Blend. In Visual Studio I have installed an the File Nesting extion (created by Mads Kristensen). This extension will automatically nest the codefile in the xaml file. It is not necessary but I like a clean solution. The complete structure of my Solution looks likes this:

Solution Explorer

Now you must add an x:Class attribute to the ResourceDictionary element in the MyDataTemplates.xaml file. This attribute points to the ResourceDictionaryWithCodeBehindDemo.Resources.MyDataTemplate class. Next you can move the ProductDataTemplate from the MainPage to the ResourceDictionary.

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="ResourceDictionaryWithCodeBehindDemo.Resources.MyDataTemplates"
        xmlns:local="using:ResourceDictionaryWithCodeBehindDemo">

    <DataTemplate x:Key="ProductDataTemplate">
        <StackPanel Orientation="Horizontal">
            <Image Source="{Binding ImageUrl}"
                   PointerEntered="Image_PointerEntered"
                   PointerExited="Image_PointerExited"
                   Opacity="0.3"
                   Width="100"
                   Height="100" />
            <StackPanel Margin="20,0">
                <TextBlock Text="{Binding Name}"
                           FontSize="30" />
                <TextBlock Text="{Binding Price}"
                           FontSize="20" />
            </StackPanel>
        </StackPanel>
    </DataTemplate>

</ResourceDictionary>

The MyDataTemplate class must be a partial class. You must also add a constructor (use the ctor snippet) to the class and call InitializeComponent(). This InitializeComponent method will be automatically generated if you set the x:Class attribute in the XAML. Finally you can move the eventhandlers from the MainPage to the MyDataTemplates class.

using System;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Input;

namespace ResourceDictionaryWithCodeBehindDemo.Resources {
    partial class MyDataTemplates {

        public MyDataTemplates() {
            this.InitializeComponent();
        }

        private void Image_PointerEntered(object sender, PointerRoutedEventArgs e) {
            var img = sender as Image;
            img.Opacity = 1.0;
        }

        private void Image_PointerExited(object sender, PointerRoutedEventArgs e) {
            var img = sender as Image;
            img.Opacity = 0.3;
        }
    }
}

The App.xaml must also be changed. You will have to register an extra xml namespace named res which holds the 'using:ResourceDictionaryWithCodeBehindDemo.Resources' value. In the MergedDictionaries element you must remove the MyDataTemplates ResourceDictionary and add an <res:MyDataTemplates /> element. This will instantiate an instance of the CodeBehind class. The constructor of the class will load the XAML in the InitializeComponent() method.

<Application
    x:Class="ResourceDictionaryWithCodeBehindDemo.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    
    xmlns:res="using:ResourceDictionaryWithCodeBehindDemo.Resources"
    
    xmlns:local="using:ResourceDictionaryWithCodeBehindDemo">
    
	<Application.Resources>
		<ResourceDictionary>
			<ResourceDictionary.MergedDictionaries>
				<!--<ResourceDictionary Source="Resources/MyDataTemplates.xaml"/>-->
                <res:MyDataTemplates />
			</ResourceDictionary.MergedDictionaries>
		</ResourceDictionary>
	</Application.Resources>

</Application>

The MainPage.xaml now doesn't have the ProductsDataTemplate.

<Page x:Class="ResourceDictionaryWithCodeBehindDemo.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="using:ResourceDictionaryWithCodeBehindDemo"
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:vm="using:ResourceDictionaryWithCodeBehindDemo.ViewModels"
      mc:Ignorable="d">

    <Page.DataContext>
        <vm:MainViewModel />
    </Page.DataContext>

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <ListView Margin="50"
                  ItemsSource="{Binding Products}"
                  ItemTemplate="{StaticResource ProductDataTemplate}">
        </ListView>
    </Grid>
</Page>

MainPage.xaml.cs now only contains the constructor.

public sealed partial class MainPage : Page {

    public MainPage() {
        this.InitializeComponent();
    }
}

Closure and download

I hope you like my solution it will open up a lot of extra possibilities to structure your XAML projects. You can download the sample project below.

Cheers,

Fons

Tags: XAML, Blend, Apps, CSharp

TechDays 2014 videos and presentations

0 Comments
By Fons Sonnemans, 31-5-2014

Op 16 en 17 april heb ik weer bij het TechDays 2014 event van Microsoft een aantal sessies gepresenteerd. Via deze blog wil ik de videos en presentaties met u delen.

What’s new in XAML and Tooling for Windows 8.1?

Channel 9 Video

SlideShare presentatie

Making money with Apps

Channel 9 Video

SlideShare presentatie

Designing XAML Apps using Blend for Visual Studio 2013

Channel 9 Video

SlideShare presentatie

 

Cheers,

Fons

Tags: TechDays, Apps, Blend, XAML

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