Control Focus on an ASP.NET Web Server control is lost after AutoPostBack

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Article ID: 810203 - View products that this article applies to.
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SYMPTOMS

When you press the TAB key on an ASP.NET Web Server control, the Web page is posted back to the Web server. After the operation is complete, the focus is not set to any control. You expect the focus to be set to the next control.

CAUSE

This problem occurs because the AutoPostBack property of the control is set to True.

STATUS

This behavior is by design.

MORE INFORMATION

If the AutoPostBack property is set to True, postback occurs when you press ENTER or when the control loses the focus after the contents are modified.

To work around this behavior:
  1. In the HTML view of WebForm1.aspx, replace the existing code with the following:

    Visual C# .NET Code
    <%@ Page Language="C#" AutoEventWireup="false" Codebehind="WebForm1.aspx.cs" Inherits="WebApplication11.WebForm1"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
    <HTML>
       <body>
          <form id="Form1" method="post" runat="server">
    	 <asp:Label id="Label1" runat="server" style="LEFT: 10px; POSITION: absolute; TOP: 20px">Label</asp:Label>
    	 <asp:textbox id="TextBox1" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 23px"></asp:textbox>
    	 <asp:Label id="Label2" runat="server" style="LEFT: 11px; POSITION: absolute; TOP: 54px">Label</asp:Label><asp:textbox id="TextBox2" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 58px"></asp:textbox>
    	 <asp:Label id="Label3" runat="server" style="LEFT: 12px; POSITION: absolute; TOP: 95px">Label</asp:Label><asp:textbox id="TextBox3" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 96px"></asp:textbox>
    	 <asp:Button id="Button1" runat="server" Text="Button" style="LEFT: 85px; POSITION: absolute; TOP: 136px"></asp:Button>
          		<script language="javascript">
    			document.all["<%= Focus %>"].focus();
    			if("<%= ControlType %>" == "TextArea")
    				document.all["<%= Focus %>"].select();
    		</script>
    	</form>
       </body>
    </HTML>
    Visual Basic .NET Code
    <%@ Page Language="vb" AutoEventWireup="false" Codebehind="WebForm1.aspx.vb" Inherits="WebApplication11.WebForm1"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
    <HTML>
       <body>
          <form id="Form1" method="post" runat="server">
    	 <asp:Label id="Label1" runat="server" style="LEFT: 10px; POSITION: absolute; TOP: 20px">Label</asp:Label>
    	 <asp:textbox id="TextBox1" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 23px"></asp:textbox>
    	 <asp:Label id="Label2" runat="server" style="LEFT: 11px; POSITION: absolute; TOP: 54px">Label</asp:Label><asp:textbox id="TextBox2" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 58px"></asp:textbox>
    	 <asp:Label id="Label3" runat="server" style="LEFT: 12px; POSITION: absolute; TOP: 95px">Label</asp:Label><asp:textbox id="TextBox3" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 96px"></asp:textbox>
    	 <asp:Button id="Button1" runat="server" Text="Button" style="LEFT: 85px; POSITION: absolute; TOP: 136px"></asp:Button>
    		<script language="javascript">
    			document.all["<%= Focus %>"].focus();
    			if("<%= ControlType %>" == "TextArea")
    				document.all["<%= Focus %>"].select();
    		</script>
          </form>
       </body>
    </HTML>
  2. In Solution Explorer, right-click WebForm1.aspx, and then click View Code.
  3. In the code-behind class, replace the existing code with the following:

    Visual C# .NET Code
    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 WebApplication22
    {
    	public class WebForm1 : System.Web.UI.Page
    	{
    		protected System.Web.UI.WebControls.Label Label1;
    		protected System.Web.UI.WebControls.TextBox TextBox1;
    		protected System.Web.UI.WebControls.Label Label2;
    		protected System.Web.UI.WebControls.TextBox TextBox2;
    		protected System.Web.UI.WebControls.Label Label3;
    		protected System.Web.UI.WebControls.TextBox TextBox3;
    		protected System.Web.UI.WebControls.Button Button1;
    		protected string Focus;
    		protected string ControlType;
    
    		private void Page_Load(object sender, System.EventArgs e)
    		{
    			Focus = "TextBox1";
    			ControlType = "TextArea";
    		}
    
    		#region Web Form Designer generated code
    		override protected void OnInit(EventArgs e)
    		{
    			InitializeComponent();
    			base.OnInit(e);
    		}
    		
    		private void InitializeComponent()
    		{    
    			this.TextBox1.TextChanged += new System.EventHandler(this.TextBox1_TextChanged);
    			this.TextBox2.TextChanged += new System.EventHandler(this.TextBox2_TextChanged);
    			this.TextBox3.TextChanged += new System.EventHandler(this.TextBox3_TextChanged);
    			this.Load += new System.EventHandler(this.Page_Load);
    		}
    		#endregion
    
    		private void TextBox1_TextChanged(object sender, System.EventArgs e)
    		{
    			Focus = "TextBox2";
    			ControlType = "TextArea";
    		}
    		
    		private void TextBox2_TextChanged(object sender, System.EventArgs e)
    		{
    			Focus = "TextBox3";
    			ControlType = "TextArea";
    		}
    		
    		private void TextBox3_TextChanged(object sender, System.EventArgs e)
    		{
    			Focus = "Button1";
    			ControlType = "Button";
    		}
    	}
    }
    
    Visual Basic .NET Code
    Public Class WebForm1
       Inherits System.Web.UI.Page
       Protected WithEvents Label1 As System.Web.UI.WebControls.Label
       Protected WithEvents TextBox1 As System.Web.UI.WebControls.TextBox
       Protected WithEvents Label2 As System.Web.UI.WebControls.Label
       Protected WithEvents TextBox2 As System.Web.UI.WebControls.TextBox
       Protected WithEvents Label3 As System.Web.UI.WebControls.Label
       Protected WithEvents TextBox3 As System.Web.UI.WebControls.TextBox
       Protected WithEvents Button1 As System.Web.UI.WebControls.Button
       Protected Focus As String
       Protected ControlType As String
    
    #Region " Web Form Designer Generated Code "
    
       'This call is required by the Web Form Designer.
       <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
    
       End Sub
    
       Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
          'CODEGEN: This method call is required by the Web Form Designer
          'Do not modify it using the code editor.
          InitializeComponent()
       End Sub
    
    #End Region
    
       Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          Focus = "TextBox1"
          ControlType = "TextArea"
       End Sub
       Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
          Focus = "TextBox2"
          ControlType = "TextArea"
       End Sub
    
       Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged
          Focus = "TextBox3"
          ControlType = "TextArea"
       End Sub
    
       Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.TextChanged
          Focus = "Button1"
          ControlType = "Button"
       End Sub
    End Class
    
  4. On the Build menu, click Start to view WebForm1.aspx in the browser.
  5. Type text in the text box, and then press the TAB key. The focus is set to the next control after the post back operation.

Steps to Reproduce the Behavior

  1. Create a new ASP.NET Web Application project. By default, WebForm1.aspx is created.
  2. In the HTML view of WebForm1.aspx, replace the existing code with the following code:

    Visual C# .NET Code
    <%@ Page Language="C#" AutoEventWireup="false" Codebehind="WebForm1.aspx.cs" Inherits="WebApplication11.WebForm1"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
    <HTML>
       <body>
          <form id="Form1" method="post" runat="server">
    	 <asp:Label id="Label1" runat="server" style="LEFT: 10px; POSITION: absolute; TOP: 20px">Label</asp:Label>
    	 <asp:textbox id="TextBox1" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 23px"></asp:textbox>
    	 <asp:Label id="Label2" runat="server" style="LEFT: 11px; POSITION: absolute; TOP: 54px">Label</asp:Label><asp:textbox id="TextBox2" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 58px"></asp:textbox>
    	 <asp:Label id="Label3" runat="server" style="LEFT: 12px; POSITION: absolute; TOP: 95px">Label</asp:Label><asp:textbox id="TextBox3" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 96px"></asp:textbox>
    	 <asp:Button id="Button1" runat="server" Text="Button" style="LEFT: 85px; POSITION: absolute; TOP: 136px"></asp:Button>
          </form>
       </body>
    </HTML>
    Visual Basic .NET Code
    <%@ Page Language="vb" AutoEventWireup="false" Codebehind="WebForm1.aspx.vb" Inherits="WebApplication11.WebForm1"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
    <HTML>
       <body>
          <form id="Form1" method="post" runat="server">
    	 <asp:Label id="Label1" runat="server" style="LEFT: 10px; POSITION: absolute; TOP: 20px">Label</asp:Label>
    	 <asp:textbox id="TextBox1" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 23px"></asp:textbox>
    	 <asp:Label id="Label2" runat="server" style="LEFT: 11px; POSITION: absolute; TOP: 54px">Label</asp:Label><asp:textbox id="TextBox2" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 58px"></asp:textbox>
    	 <asp:Label id="Label3" runat="server" style="LEFT: 12px; POSITION: absolute; TOP: 95px">Label</asp:Label><asp:textbox id="TextBox3" runat="server" AutoPostBack="True" style="LEFT: 85px; POSITION: absolute; TOP: 96px"></asp:textbox>
    	 <asp:Button id="Button1" runat="server" Text="Button" style="LEFT: 85px; POSITION: absolute; TOP: 136px"></asp:Button>
          </form>
       </body>
    </HTML>
  3. On the Debug menu, click Start to run the project.

REFERENCES

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
314206 PRB: Controls Lose Focus When You Enable SmartNavigation and AutoPostBack
For more information, visit the following Microsoft Developer Network (MSDN) Web site:
TextBox.AutoPostBack Property
http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.textbox.autopostback(vs.71).aspx

Properties

Article ID: 810203 - Last Review: February 28, 2012 - Revision: 2.0
APPLIES TO
  • Microsoft ASP.NET 4
  • Microsoft ASP.NET 2.0
  • Microsoft ASP.NET 1.1
  • Microsoft Visual Basic .NET 2003 Standard Edition
  • Microsoft Visual C# .NET 2003 Standard Edition
  • Microsoft ASP.NET 1.0
  • Microsoft Visual Basic .NET 2002 Standard Edition
  • Microsoft Visual C# .NET 2002 Standard Edition
Keywords: 
kbprb kbwebforms KB810203

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