Blog posts by Fons Sonnemans, page 21

By Fons Sonnemans

The NumberBox control is an ASP.NET control, which lets the user only input numerical values. The base class of NumberBox class is the TextBox class. It uses JavaScript to validate the KeyPress event. An extra RegularExpresionValidator can be used to validate the control.

Special public properties:

AllowNegatives
DecimalPlaces
DecimalSymbol
Text
Value
ValidationRegularExpression

Demo

Number:

Sample Project

NumberBox Class

using System;
using System.Web.UI;
using System.ComponentModel;
using System.Web.UI.WebControls;
using System.Text;
using System.Text.RegularExpressions;

namespace NumberBoxDemo
{
    /// <summary>
    /// Number Box ASP.NET control
    ///
    /// Created by Fons Sonnemans, Reflection IT
    ///
    /// Be sure to notice that this code is provided as a technology sample
    /// and 'as is', no warranties are made by the author.
    ///
    /// For questions and comments: Fons.Sonnemans@reflectionit.nl
    ///
    /// </summary>
    [
    ToolboxData("<{0}:NumberBox runat=server></{0}:NumberBox>"),
    DefaultProperty("DecimalPlaces")
    ]
    publicclass NumberBox : TextBox
    {

        privateintmDecimalPlaces=0;
        privatecharmDecimalSymbol='.';
        privateboolmAllowNegatives=true;

        /// <summary>
        /// Gets or sets the number of decimals for the number box.
        /// </summary>
        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue(0),
        Description("Indicates the number of decimal places to display.")
        ]
        publicvirtualint DecimalPlaces
        {
            get{return mDecimalPlaces;}
            set{mDecimalPlaces=value;}
        }

        /// <summary>
        /// Gets or sets the digit grouping symbol for the number box.
        /// </summary>
        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue("."),
        Description("The digit grouping symbol.")
        ]
        publicvirtualchar DecimalSymbol
        {
            get{return mDecimalSymbol;}
            set{mDecimalSymbol=value;}
        }

        /// <summary>
        /// Gets or sets wheter negative numbers are allowed in the number box.
        /// </summary>
        [
        Bindable(true),
        Category("Appearance"),
        DefaultValue(true),
        Description("True when negative values are allowed")
        ]
        publicvirtualbool AllowNegatives
        {
            get{return mAllowNegatives;}
            set{mAllowNegatives=value;}
        }

        /// <summary>
        /// Gets or sets the value of the number box.
        /// </summary>
        publicvirtualdouble Value
        {
            get
            {
                try
                {
                    return ParseStringToDouble(this.Text);
                }
                catch(FormatException e)
                {
                    thrownew
                    InvalidOperationException("NumberBox does nog contain a valid Number.");
                }
                catch(Exception e)
                {
                    throw e;
                }

            }
            set
            {
                if((value < 0)&!AllowNegatives)
                    thrownew
                    ArgumentOutOfRangeException("
                    Only positivevaluesareallowedforthis NumberBox");

                //base.Text = value.ToString(this.Format);
                base.Text =value.ToString(GetFormat()).Replace(".", DecimalSymbol.ToString());
            }
        }

        /// <summary>
        /// Gets or sets the text content of the number box.
        /// </summary>
        overridepublicstring Text
        {
            get
            {
                returnbase.Text;
            }
            set
            {
                try{
                    this.Value = ParseStringToDouble(value);
                }catch (FormatException e) {
                    base.Text =value;
                }
                catch(Exception e)
                {
                    throw e;
                }
            }
        }

        /// <summary>
        ///    Add a JavaScript to the Page and call it from the onKeyPress event
        /// </summary>
        /// <param name="e"></param>
        overrideprotectedvoid OnPreRender(EventArgs e) {

            if(this.Page.Request.Browser.JavaScript ==true)
            {
                // Build JavaScript
                StringBuilder s =new StringBuilder();
                s.Append("\n<script type='text/javascript' language='JavaScript'>\n");
                s.Append("\n");
                s.Append("</script>\n");

                // Add the Script to the Page
                this.Page.RegisterClientScriptBlock("NumberBoxKeyPress", s.ToString());

                // Add KeyPress Event
                try{
                    this.Attributes.Remove("onKeyPress");
                }finally {
                    this.Attributes.Add("onKeyPress","return NumberBoxKeyPress(event, "
                                        + DecimalPlaces.ToString() +", "
                                        +((int)DecimalSymbol).ToString()+", "
                                        + AllowNegatives.ToString().ToLower() +")");
                }
            }
        }

        /// <summary>
        /// Returns the RegularExpression string which can be used for validating
        /// using a RegularExpressionValidator.
        /// </summary>
        virtualpublicstring ValidationRegularExpression
        {
            get
            {
                StringBuilder regexp= new StringBuilder();

                if(AllowNegatives)
                    regexp.Append("([-]|[0-9])");

                regexp.Append("[0-9]*");

                if(DecimalPlaces > 0)
                {
                    regexp.Append("([");
                    regexp.Append(DecimalSymbol);
                    regexp.Append("]|[0-9]){0,1}[0-9]{0,");
                    regexp.Append(DecimalPlaces.ToString());
                    regexp.Append("}$");
                }

                returnregexp.ToString();
            }
        }

        /// <summary>
        /// Parse a String to a Double
        /// </summary>
        /// <param name="s">string to be parsed to a double</param>
        /// <returns>double value</returns>
        virtualprotecteddouble ParseStringToDouble(string s)
        {
            s = s.Replace(DecimalSymbol.ToString(),".");
            returndouble.Parse(s);
        }

        /// <summary>
        /// Returns the FormatString used to display the value in the number box
        /// </summary>
        /// <returns>Format string</returns>
        virtualprotectedstring GetFormat()
        {
            StringBuilder f =new StringBuilder();
            f.Append("0");
            if(DecimalPlaces > 0)
            {
                f.Append(".");
                f.Append('0', DecimalPlaces);
            }

            return f.ToString();
        }

    }
}

Validation

You can use a normal RegularExpressionValidator control to validate the NumberBox. Invalid nummers are then rejected without causing a roundtrip to the server. Invalid numbers can still be entered using the clipboard Paste option. I don't know how to avoid this.

You can use the NumberBox.ValidationRegularExpression property to set the RegularExpressionValidator.ValidationRegularExpression property to the correct RegularExpression.

        private voidPage_Load(objectsender, System.EventArgs e)
        {
            if(!IsPostBack)
            {
                valOne.ValidationExpression=numOne.ValidationRegularExpression;
                valTwo.ValidationExpression=numTwo.ValidationRegularExpression;
            }
        }

WebForm1.aspx

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false"
Inherits="NumberBoxDemo.WebForm1"%>
<%@ Register TagPrefix="rit" Namespace="NumberBoxDemo" Assembly="NumberBoxDemo"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <metacontent="Microsoft Visual Studio 7.0"name="GENERATOR">
        <metacontent="C#"name="CODE_LANGUAGE">
        <metacontent="JavaScript (ECMAScript)"name="vs_defaultClientScript">
        <metacontent="http://schemas.microsoft.com/intellisense/ie5"name="vs_targetSchema">
    </HEAD>
    <body style="FONT-FAMILY: Verdana">
        <formid="Form1"method="post"runat="server">
            <H2>
                NumberBox Demo Page
            </H2>
            <P>
                <TABLE cellSpacing="1"cellPadding="1"width="100%"border="0">
                    <TR>
                        <TD style="WIDTH: 300px">
                            Numberbox1:
                        </TD>
                        <TD>
                            <rit:numberboxid="numOne"runat="server" DecimalSymbol=","
                             MaxLength="8" DecimalPlaces="2">
                                32,46
                            </rit:numberbox>
                        </TD>
                        <TD>
                            <asp:regularexpressionvalidatorid="valOne"runat="server"
                            ControlToValidate="numOne">
                            Invalid Number</asp:regularexpressionvalidator>
                        </TD>
                    </TR>
                    <TR>
                        <TD style="WIDTH: 300px"vAlign="top">
                            <FONT size="1">(Double, 2decimals,',' DecimalSymbol)</FONT>
                        </TD>
                        <TD>
                        </TD>
                        <TD>
                        </TD>
                    </TR>
                    <TR>
                        <TD style="WIDTH: 300px">
                             
                        </TD>
                        <TD>
                        </TD>
                        <TD>
                        </TD>
                    </TR>
                    <TR>
                        <TD style="WIDTH: 300px">
                            Numberbox2:
                        </TD>
                        <TD>
                            <rit:numberboxid="numTwo"runat="server" MaxLength="8"
                             DecimalSymbol="." AllowNegatives="False">
                            </rit:numberbox>
                        </TD>
                        <TD>
                            <asp:RegularExpressionValidator id="valTwo"runat="server"
                            ControlToValidate="numTwo">
                            Invalid Number</asp:RegularExpressionValidator>
                        </TD>
                    </TR>
                    <TR>
                        <TD style="WIDTH: 300px"vAlign="top">
                            <FONT size="1">(Poisitive Integer)</FONT>
                        </TD>
                        <TD>
                        </TD>
                        <TD>
                        </TD>
                    </TR>
                    <TR>
                        <TD style="WIDTH: 300px">
                        </TD>
                        <TD>
                        </TD>
                        <TD>
                        </TD>
                    </TR>
                </TABLE>
            </P>
            <P>
            </P>
            <P>
                <asp:buttonid="btnSubmit"runat="server" Text="Submit"></asp:button>
            </P>
            <P>
                <asp:PlaceHolder id="PlaceHolder1"runat="server"></asp:PlaceHolder>
            </P>
            <P>
            </P>
        </form>
    </body>
</HTML>

WebForm1.aspx.cs

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace NumberBoxDemo
{
    /// <summary>
    /// Summary description for WebForm1.
    /// </summary>
    public class WebForm1: System.Web.UI.Page
    {
        protected NumberBoxDemo.NumberBox numOne;
        protected System.Web.UI.WebControls.RegularExpressionValidator valOne;
        protected NumberBoxDemo.NumberBox numTwo;
        protected System.Web.UI.WebControls.RegularExpressionValidator valTwo;
        protected System.Web.UI.WebControls.PlaceHolder PlaceHolder1;
        protected System.Web.UI.WebControls.Button btnSubmit;

        public WebForm1()
        {
            Page.Init +=new System.EventHandler(Page_Init);
        }

        privatevoid Page_Load(objectsender, System.EventArgs e)
        {
            // Put user code to initialize the page here

            if(!IsPostBack)
            {
                valOne.ValidationExpression =numOne.ValidationRegularExpression;
                valTwo.ValidationExpression =numTwo.ValidationRegularExpression;
            }
        }

        privatevoid Page_Init(objectsender, EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
        }

        #region Web Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        privatevoid InitializeComponent()
        {
            this.btnSubmit.Click += new System.EventHandler(this.btnSubmit_Click);
            this.Load +=new System.EventHandler(this.Page_Load);

        }
        #endregion

        privatevoidbtnSubmit_Click(object sender, System.EventArgs e)
        {
            numTwo.Value = new Random().NextDouble()*1000;

            this.PlaceHolder1.Controls.Clear();
            this.PlaceHolder1.Controls.Add(new LiteralControl(
             "Numberbox1.Value = "
             +numOne.Value.ToString()+"<br>"));
            this.PlaceHolder1.Controls.Add(new LiteralControl(
             "Numberbox1.Text = "
             +numOne.Text +"<br>"));
            this.PlaceHolder1.Controls.Add(new LiteralControl(
             "Numberbox1.ValidationRegularExpression = "
             +numOne.ValidationRegularExpression +"<br>"));
        }

    }
}

Any suggestions and feedback for improving this article is most welcome. Send your suggestions and feedback to Fons.Sonnemans@reflectionit.nl

By Fons Sonnemans

Download LocalizedText.zip

The CreateProperty macro is simple Visual Studio.Net (Final) macro which can be used to generate the code for a 'private Field and a public Property Get/Set method'.

Example:

1.	Unzip the ReflectionIT macro.zip
2.	Start Visual Studio.Net.
3.	Open the Macro Explorer (Alt-F8)
4.	Right-click on the Macros, and select 'Load Macro Project...'

5.	Select the (unzipped) 'ReflectionIT.vsmacros' file and select 'Open'.
6.	Open a CodeWindow and add a public, private or protected field. Example:

7.	Select the text you just have entered and run the 'CreateProperty' macro

8.	Your text is automatically replaced by a private field and an public property

Any suggestions and feedback for improving this article is most welcome. Send your suggestions and feedback to Fons.Sonnemans@reflectionit.nl

By Fons Sonnemans

Download StockServices.zip

The Stock Sample Web Service uses the Html2Xml service to retrieve the Finance page of Yahoo. It then searches the Xml, using an XPath expression, for the current value and returns it. Hopefully Yahoo never changes their HTML structure.

VB.NET Source Code

Imports System.Web.Services
Imports System.Xml
Imports Html2XmlService <_o3a_p>

Namespace ReflectionIT.WebServices.StockServices <_o3a_p />

<WebService(Namespace:="http://www.reflectionit.nl/webservices/", Description:="StockServices created by Reflection IT.")> _
Public Class StockServices <_o3a_p>

Inherits System.Web.Services.WebService <_o3a_p>

Public Sub New()
   MyBase.New()
   'This call is required by the Web Services Designer.
   InitializeComponent()
   'Add your own initialization code after the InitializeComponent() call
End Sub <_o3a_p />

'Required by the Web Services Designer
Private components As System.ComponentModel.Container <_o3a_p>

'NOTE: The following procedure is required by the Web Services Designer
'It can be modified using the Web Services Designer.
'Do not modify it using the code editor. <_o3a_p />

<System.Diagnostics.DebuggerStepThrough()>_
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub <_o3a_p />

Protected Overloads Overrides Sub Dispose(ByVal disposing AsBoolean)
'CODEGEN: This procedure is required by the Web Services Designer
'Do not modify it using the code editor.
End Sub <_o3a_p />

<WebMethod(Description:="Get the Yahoo stock quote.")> _
Public Function GetStockQuote(ByVal symbol AsString) AsDouble <_o3a_p />

' Build the Url
Dim url AsString = "http://finance.yahoo.com/q?s=" + symbol + "&d=v1" <_o3a_p />

   ' Get the XmlDocument using the Html2Xml WebServices
   Dim xml As XmlDocument = New XmlDocument()
   xml.LoadXml(New Html2XmlService.Html2XmlServices().Url2XmlString(url)) <_o3a_p />

' Find the Nodes using a XPath expression
Dim l As XmlNodeList = xml.SelectNodes("/html/body/center/table/tr/td/table/tr/td/b") <_o3a_p />

   ' Validate and return value
   If (l.Count <> 2) Then
Throw New Exception("symbol not found.")
   End If
   Return Double.Parse(l(1).InnerXml) <_o3a_p />

End If <_o3a_p />

End Function <_o3a_p />

End Class <_o3a_p />

End Namespace

Any suggestions and feedback for improving this article is most welcome. Send your suggestions and feedback to Fons.Sonnemans@reflectionit.nl

By Fons Sonnemans

Download ProcedureSort.zip

The Procedures Sort Add-In is a great add-in for those who like well-organized code. You can use it to sort your procedures in the active CodeWindow alphabetically. It preserve all you procedure attributes, which you normally loose when you do it manually. Event-handlers and Interface-implementations will be placed at the end of your code.

Install & Usage:

1.	Unzip the ProcedureSort.zip
2.	Register the ProcedureSort.dll you just unzipped using Regsvr32.exe.
3.	Start Visual Basic 6.0.
4.	Select menu 'Add-Ins', 'Add-in Manager...'.

5.	You see now an extra button in your Standard toolbar.
6.	Open a CodeWindow. Example:

7.	Click on the new 'Sort Procedures' toolbar button. All procedures will be sorted alphabetically.

8.	You can set the following options (Menu 'Add-Ins', 'Procedure Sort Options...'): - Show Constructor and Destructor at top - Case Sensitive - Number of empty lines between procedures

By Fons Sonnemans

Download OutlookAgent.zip

You can use Microsoft Agent in Outlook 2000 to read your incoming mail.

Requirements:

Microsoft Outlook 2000
Microsoft Agent
Microsoft Agent Characters
Lernout & Hauspie TruVoice Text-to-Speech (TTS) Engine

For more information about installing MS Agent software have a look at: http://www.msagentring.org/setup.htm

10 Steps:

1.	Install the requirements.
2.	Download this Zipfile and Unzip the CAgent.cls file to a folder (c:\temp).
3.	Select in 'Outlook 2000' the menu option 'Tools', 'Macro', 'Visual Basic Editor???' or press 'Alt-F11'.
4.	Select in the 'Microsoft Visual Basic' editor menu 'Tools', 'References???'.

5.	Check the checkboxes in front off 'Microsoft Agent Control 2.0' and 'Microsoft Scripting Runtime'.
6.	Open the 'File' menu and select the option 'Import File???'.

7.	Select the CAgent.cls file and select Open.

	The project explorer should look like:

8.	Add the following code to the (existing) ThisOutlookSession.

9.	Save the project by clicking the 'Save' button in the toolbar.

10.	Close de 'Microsoft Visual Basic' Editor. MS Agent will now read your incoming e-mails. You can easily test it by sending a mail to yourself.

By Fons Sonnemans

Introduction

As you probably know, HTML is a "markup language" that uses "tags" (such as and <br> and <p>) to mark up text for formatting. The Extensible Markup Language (XML) is the universal format for structured documents and data on the Web.

Both HTML and XML use <, >, and & to create element and attribute structures. While HTML browsers accept or ignore mangled markup language, XML parsers and applications built on those parsers are less forgiving

The Html2Xml webservice takes an Html text and converts it into an Xml text. Some corrections are done to the Html to make it well-formed Xml.

You can use this webservice to screen scrape a web page and convert it to Xml. The Xml can then be used for further processing.

The Html2Xml is also registered in the UDDI registry.

Operations

The following operations are supported. For a formal definition, please review the Service Description.

HtmlString2XmlNode
Public: Convert the Html string to an XmlNode.
HtmlString2XmlString
Public: Convert the Html string to an Xml string.
Url2XmlNode
Public: Convert the Html page with the given Url to an XmlNode.
Url2XmlString
Public: Convert the Html page with the given Url to an Xml string.
VersionInfo
Public: Returns the web service name, current version, date and copyright information.
ReportStatistics
Private: Return usage statistics, this operation requires a Key.

Buy the Hmtl2Xml Library

Given the success of the Html2Xml on the web, Reflection IT released the 'Html2Xml Library' product. More info...

Corrections

The Html2Xml webservice corrects the markup so that it matches the observed rendering in popular browsers from Netscape and Microsoft as much as possible. Here are just a few examples of how Html2Xml perfects your HTML for you:

Match the case of the start and end tags
The case of a start and end tags must match. Html2Xml writes all tags in lower case.

HTML	Corrected XML
<P>here is a paragraph with a <b>bold</B> word</p>	<p>here is a paragraph with a <b>bold</b> word</p>

End tags in the wrong order are corrected:
XML does not allow start and end tags to overlap, but enforces a strict hierarchy within the document. Html2Xml corrects this as much as possible.

HTML	Corrected XML
<table> <tr> <td> text </tr> </td> </table>	<table> <tr> <td> text </td> </tr> </table>

Non-empty elements are closed
All elements must be closed, explicitly or implicitly. Many people used the <p> tag to separate paragraphs. The <p> tag is designed to mark the beginning and end of a paragraph. That makes it a "non-empty" tag since it contains the paragraph text. Html2Xml add the end tag to all non-empty tags.

Affected Elements: <basefont>, <body>, <colgroup>, <dd>, <dt>, <head>, <html>, <li>, <p>, <tbody>/<thead>/<tfoot>, <th>/<td>, <tr>.

HTML	Corrected XML
<ul> <li> Bullet 1 <li> Bullet 2 </ul>	<ul> <li> Bullet 1 </li> <li> Bullet 2 </li> </ul>

Empty elements are terminated
While end tags may be optional with certain HTML elements, all elements in XML must have an end tag. a <br> tag is "empty" because it never contains anything. Other tags like this are <hr> and <img src="valid.gif"> Html2Xml terminates them by placing a forward slash (/) before the end bracket.

Affected Elements: <area>, <base>, <br>, <col>, <frame>, <hr>, <img>, <input>, <isindex>, <link>, <meta>, <option>, <param>.

HTML	Corrected XML
text <br> text	text <br /> text

Missing quotes around attribute values are added
All attribute values must be quoted, whether or not they contain spaces. Html2Xml inserts quotation marks around all attribute values for you.

HTML	Corrected XML
<img src=example.gif width=40 height=30>	<img src='example.gif' width='40' height='30' />

Duplicate attributes are removed
An attribute may only be used once within a start tag. Html2Xml removes duplicate attributes for you.

HTML	Corrected XML
<img src='example.gif' width='30' width='40' height='30' />	<img src='example.gif' width='30' height='30' />

Minimized attributes (used without a value) get a 'dummy' value
An attribute must have a value. Html2Xml gives attributes that have no values (e.g. nowrap, selected) a 'dummy' value.

HTML	Corrected XML
<td align='center' nowrap width='30'>	<td align='center' nowrap='value' width='30'>

Script Blocks containing unparseable characters are enclosed in a CDATA section.
Script blocks in HTML can contain unparseable characters, namely < and &. These must be escaped in well-formed HTML by enclosing the script block in a CDATA section.

HTML	Corrected XML
<SCRIPT> // checks a number against 5 function checkFive(n) { return n < 5; } </SCRIPT>	<SCRIPT><![CDATA[ // checks a number against 5 function checkFive(n) { return n < 5; } ]]></SCRIPT>

Convert built-in characters
You cannot use the characters <, >, or & within the text of your documents. Html2Xml converts them to the Xml built-in character entities. The following characters are converted:

< ??? (<)
> ??? (>)
& ??? (&)
&qout; ??? (")
'- (')

Nonbreaking spaces ( ) are converted to  

Development

The Html2Xml webservice is developed using:

Microsoft.NET framework 1.1
Microsoft Visual Studio.NET 2003
C#

Sample

The Stock Sample Web Service uses the Html2Xml service to retrieve the Finance page of Yahoo. It then searches the Xml, using an XPath expression, for the current value and returns it.

For more information see: Stock Sample Web Service

Conclusion

The Html2Xml webservice is an easy to use, powerful solution to convert Html to Xml.

Disclaimer

Reflection IT makes these WebServices available for free use without any sort of guarantees or promises of proper operation. Reflection IT cannot guarantee support of any kind to fix bugs or effect modifications based on feedback provided by the users. All that can be said is that these WebServices are being used in The Netherlands and viewers are free to use them.

Reflection IT will in no way be responsible for problems arising out of the use of the WebServices. Using them is at your own risk.

Blog

posts by Fons Sonnemans

ASP.NET NumberBox Control

Demo

Sample Project

NumberBox Class

Validation

WebForm1.aspx

WebForm1.aspx.cs

Create Property Macro for VS.NET 2002 & 2003

Example:

Stock Sample Web Service

VB.NET Source Code

Visual Basic 6.0 Procedure Sort Add-In

Install & Usage:

MS Outlook 2000 and MS Agent

Requirements:

10 Steps:

Html2Xml Web Service

Introduction

Operations

Buy the Hmtl2Xml Library

Corrections

Development

Sample

Conclusion

Disclaimer