Losing state on bound controls in user controls

22 Mar 2005 11:14 PM

Josh

I am trying to move some of my more common controls into user controls.
However, I seem to have problems maintaining state of databound
controls that are contained within user controls. On postback the
controls still display correctly. However, trying to access the
controls programatically gets me into their default (unbound) values.
I feel like I am missing something basic about creating user controls.
Any help is appreciated.

Below is a sample of what I'm running into. When clicking a button in
the repeater (which is within a user control), the value of the label
comes up as "" even though it still displays correctly as
"A","B","C","D" or "F".

Thanks in advance,
Josh

User Control Design
-----------------
<%@ Control Language="c#" AutoEventWireup="false"
Codebehind="TestControl.ascx.cs"
Inherits="WebTools.Documents.TestControl"
TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
<asp:Repeater ID="rptTest" Runat=server>
    <ItemTemplate>
        <asp:Label ID="lblTest" Runat=server><%# Container.DataItem
%></asp:Label>
        <asp:LinkButton ID="lnkTest" Runat=server
CommandName="Test">Test</asp:LinkButton>
        <br>
    </ItemTemplate>
</asp:Repeater>
<asp:Label ID="lblResult" Runat=server>
</asp:Label>

User Control CodeBehind
-----------------------

namespace WebTools.Documents
{
    using System;
    using System.Data;
    using System.Drawing;
    using System.Web;
    using System.Web.UI.WebControls;
    using System.Web.UI.HtmlControls;

    public class TestControl : System.Web.UI.UserControl
    {
        protected System.Web.UI.WebControls.Repeater rptTest;
        protected System.Web.UI.WebControls.Label lblResult;

        private void Page_Load(object sender, System.EventArgs e)
        {

        }

        public void TestBind()
        {
            string[] strTest = {"A","B","C","D","F"};
            rptTest.DataSource = strTest;
            rptTest.DataBind();

        }
        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }

        /// <summary>
        ///        Required method for Designer support - do not modify
        ///        the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.rptTest.ItemCommand += new
System.Web.UI.WebControls.RepeaterCommandEventHandler(this.rptTest_ItemCommand);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        private void rptTest_ItemCommand(object source,
System.Web.UI.WebControls.RepeaterCommandEventArgs e)
        {
            if (e.CommandName == "Test")
            {
                lblResult.Text = "Test Selected:" +
((Label)e.Item.FindControl("lblTest")).Text;
            }
        }
    }
}

Page Design
---------------

<%@ Register TagPrefix="uc1" TagName="TestControl"
Src="TestControl.ascx" %>
<%@ Page language="c#" Codebehind="TestControlPage.aspx.cs"
AutoEventWireup="false" Inherits="WebTools.Documents.TestControlPage"
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
    <title>TestControlPage</title>
    <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
    <meta name="CODE_LANGUAGE" Content="C#">
    <meta name=vs_defaultClientScript content="JavaScript">
    <meta name=vs_targetSchema
content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING="GridLayout">

    <form id="Form1" method="post" runat="server"><uc1:TestControl
id=uclTest runat="server"></uc1:TestControl>

     </form>

</body>
</HTML>

Page CodeBehind
----------------
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 WebTools.Documents
{
    public class TestControlPage : System.Web.UI.Page
    {
        protected TestControl uclTest;

        private void Page_Load(object sender, System.EventArgs e)
        {
            // Put user code to initialize the page here
            if (! IsPostBack)
            {
                uclTest.TestBind();
            }
        }

        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion
    }
}

23 Mar 2005 3:23 PM

ashish

because you are not setting Text property :)

you should set your label to <asp:label id="label1" runat="server"
text='<% Container.dataitem %>' ></asp:label>

and it should work

hth
-ashish

Josh wrote:
Show quoteHide quote

> I am trying to move some of my more common controls into user controls.
> However, I seem to have problems maintaining state of databound
> controls that are contained within user controls. On postback the
> controls still display correctly. However, trying to access the
> controls programatically gets me into their default (unbound) values.
> I feel like I am missing something basic about creating user controls.
> Any help is appreciated.
>
> Below is a sample of what I'm running into. When clicking a button in
> the repeater (which is within a user control), the value of the label
> comes up as "" even though it still displays correctly as
> "A","B","C","D" or "F".
>
> Thanks in advance,
> Josh
>
> User Control Design
> -----------------
> <%@ Control Language="c#" AutoEventWireup="false"
> Codebehind="TestControl.ascx.cs"
> Inherits="WebTools.Documents.TestControl"
> TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
> <asp:Repeater ID="rptTest" Runat=server>
>     <ItemTemplate>
>         <asp:Label ID="lblTest" Runat=server><%# Container.DataItem
> %></asp:Label>
>         <asp:LinkButton ID="lnkTest" Runat=server
> CommandName="Test">Test</asp:LinkButton>
>         <br>
>     </ItemTemplate>
> </asp:Repeater>
> <asp:Label ID="lblResult" Runat=server>
> </asp:Label>
>
>
> User Control CodeBehind
> -----------------------
>
>
> namespace WebTools.Documents
> {
>     using System;
>     using System.Data;
>     using System.Drawing;
>     using System.Web;
>     using System.Web.UI.WebControls;
>     using System.Web.UI.HtmlControls;
>
>     public class TestControl : System.Web.UI.UserControl
>     {
>         protected System.Web.UI.WebControls.Repeater rptTest;
>         protected System.Web.UI.WebControls.Label lblResult;
>
>         private void Page_Load(object sender, System.EventArgs e)
>         {
>
>         }
>
>         public void TestBind()
>         {
>             string[] strTest = {"A","B","C","D","F"};
>             rptTest.DataSource = strTest;
>             rptTest.DataBind();
>
>         }
>         #region Web Form Designer generated code
>         override protected void OnInit(EventArgs e)
>         {
>             //
>             // CODEGEN: This call is required by the ASP.NET Web Form Designer.
>             //
>             InitializeComponent();
>             base.OnInit(e);
>         }
>
>         /// <summary>
>         ///        Required method for Designer support - do not modify
>         ///        the contents of this method with the code editor.
>         /// </summary>
>         private void InitializeComponent()
>         {
>             this.rptTest.ItemCommand += new
> System.Web.UI.WebControls.RepeaterCommandEventHandler(this.rptTest_ItemCommand);
>             this.Load += new System.EventHandler(this.Page_Load);
>
>         }
>         #endregion
>
>         private void rptTest_ItemCommand(object source,
> System.Web.UI.WebControls.RepeaterCommandEventArgs e)
>         {
>             if (e.CommandName == "Test")
>             {
>                 lblResult.Text = "Test Selected:" +
> ((Label)e.Item.FindControl("lblTest")).Text;
>             }
>         }
>     }
> }
>
> Page Design
> ---------------
>
> <%@ Register TagPrefix="uc1" TagName="TestControl"
> Src="TestControl.ascx" %>
> <%@ Page language="c#" Codebehind="TestControlPage.aspx.cs"
> AutoEventWireup="false" Inherits="WebTools.Documents.TestControlPage"
> %>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
> <HTML>
>   <HEAD>
>     <title>TestControlPage</title>
>     <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
>     <meta name="CODE_LANGUAGE" Content="C#">
>     <meta name=vs_defaultClientScript content="JavaScript">
>     <meta name=vs_targetSchema
> content="http://schemas.microsoft.com/intellisense/ie5">
>   </HEAD>
>   <body MS_POSITIONING="GridLayout">
>
>     <form id="Form1" method="post" runat="server"><uc1:TestControl
> id=uclTest runat="server"></uc1:TestControl>
>
>      </form>
>
>   </body>
> </HTML>
>
> Page CodeBehind
> ----------------
> 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 WebTools.Documents
> {
>     public class TestControlPage : System.Web.UI.Page
>     {
>         protected TestControl uclTest;
>
>         private void Page_Load(object sender, System.EventArgs e)
>         {
>             // Put user code to initialize the page here
>             if (! IsPostBack)
>             {
>                 uclTest.TestBind();
>             }
>         }
>
>         #region Web Form Designer generated code
>         override protected void OnInit(EventArgs e)
>         {
>             //
>             // CODEGEN: This call is required by the ASP.NET Web Form Designer.
>             //
>             InitializeComponent();
>             base.OnInit(e);
>         }
>
>         /// <summary>
>         /// Required method for Designer support - do not modify
>         /// the contents of this method with the code editor.
>         /// </summary>
>         private void InitializeComponent()
>         {
>             this.Load += new System.EventHandler(this.Page_Load);
>
>         }
>         #endregion
>     }
> }
>