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TextBox.TextChanged Event

Occurs when the user changes the text of a TextBox. This API is obsolete. For information about how to develop ASP.NET mobile applications, see the Web site.

Namespace:  System.Web.UI.MobileControls
Assembly:  System.Web.Mobile (in System.Web.Mobile.dll)

public event EventHandler TextChanged
<asp:TextBox OnTextChanged="EventHandler" />

When the user changes the text of a TextBox, this event is not raised immediately. The form must contain a Command to initiate a postback event that raises the TextChanged event.

The following example demonstrates how to use the TextChanged event to change the items in a SelectionList.

<%@ Page Language="C#" 
    Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register TagPrefix="mobile" 
    Assembly="System.Web.Mobile" %>

<script runat="server">
    void Page_Load(object sender, EventArgs e)
        if (!IsPostBack)
            // Add items to the list
                MobileListItem("Verify transactions","Done"));
                MobileListItem("Check balance sheet","Scheduled"));
                MobileListItem("Call customer", "Done"));
                MobileListItem("Send checks", "Pending"));
                MobileListItem("Send report", "Pending"));
                MobileListItem("Attend meeting", "Scheduled"));

            // Show all items in list
            SelectionList1.Rows = SelectionList1.Items.Count;
    void TextChanged(object sender, EventArgs e)
        // Called during PostBack, if changed
        string task = TextBox1.Text;
        string status = TextBox2.Text;

        if (task.Length > 0 && status.Length > 0)

            MobileListItem li = new MobileListItem(task, status);

            // Remove the item if it exists
            if (SelectionList1.Items.Contains(li))
                // Add the item if it does not exist

            // Clear the text boxes
            TextBox1.Text = String.Empty;
            TextBox2.Text = String.Empty;

        // Display all items.
        SelectionList1.Rows = SelectionList1.Items.Count;

<html xmlns="" >
    <mobile:Form id="Form1" runat="server">
        <mobile:Label Id="Label1" runat="server">
            Create a new Task with Status</mobile:Label>   
        <mobile:SelectionList runat="server" BreakAfter="true" 
            id="SelectionList1" />
        <mobile:Label Id="Label2" runat="server" 
            Text="Enter the Task name" />
        <mobile:TextBox runat="server" id="TextBox1" 
            OnTextChanged="TextChanged" />
        <mobile:Label Id="Label3" runat="server" 
            Text="Enter the Task status" />
        <mobile:TextBox runat="server" id="TextBox2" />
        <mobile:Command ID="Command1" runat="server" 
            Text="Submit" />

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.