How to access textbox, label inside update panel from code behind using asp.net web forms

Question

I have a few controls defined inside an update panel which are bound to repeater control. I need to hide and show the user name and country based on anonymous fields, but the problem is that I'm not able to access the controls defined inside update panel programmatically.

How can I access these controls, I looked on the net also but couldn't find many references

Below is the code from aspx page and .cs page

<asp:UpdatePanel ID="updPnlComments" runat="server">
<ContentTemplate>
<table border="0" width="100%" ><tr><td valign="top">
    <asp:Repeater ID="rptCommentList" runat="server" EnableViewState="false">
       <ItemTemplate>
            <div id="divComPostDate" class="ArticlePubDate">
                <asp:Label ID="lblComDateAdded" runat="server" Text="Added"></asp:Label> 
                <asp:Label ID="lblComPostDate" runat="server" Text='<%# FormatCommentDate(Eval("comPostDate")) %>'></asp:Label>
            </div>
            <div id="divComMSGDetail" class="PostCommentMSG">
                <asp:Label ID="lblComMSGDetails"  runat="server" Text='<%# Eval("comMessage") %>'></asp:Label> 
            </div>
            <div id="divComUserName" class="ComUserName">
                <asp:Label ID="lblComUserName" runat="server" Text='<%# Eval("comFullName") %>'></asp:Label>,
                <asp:Label ID="lblComCountry" runat="server" Text='<%# Eval("comCountry") %>'></asp:Label>
                <asp:Label ID="lblUserAnonymous" runat="server" Text='<%# showUserName(Eval("comAnonymous")) %>' Visible=false></asp:Label>
            </div>
            <div id="divThinlLine" class="ThinLine" ></div>
        </ItemTemplate>
     </asp:Repeater>
  </td></tr><tr><td>
    <table border="0" width="90%" ><tr><td align="center" valign="bottom" height="50px">
      <table border="0"><tr><td align="center" >
             <uc1:PagerControl ID="PagerControl1" runat="server"  CssClass="gold-pager"  PageMode="LinkButton"  />
      </td></tr></table>
    </td></tr></table>
</td></tr></table>
</ContentTemplate>
</asp:UpdatePanel>

Code Behind

protected string FormatCommentDate(object dt)
{
    string date;
    date  = String.Format("{0:hh:mm, MMMM dd, yyyy}", dt);
    return date;
}

protected string showUserName(object userName)
{
    String str=null;
    try
    {
        Boolean isUserAnonymous = Convert.ToBoolean(userName);

        if (isUserAnonymous == true)
        {
            // Not able to access lblComUserName CONTROL here

        }

    }
    catch (Exception ex)
    {

    }

    return str;

}

Function To bind repeater control with Pager and Repeater control

protected void getCommentsList(int iArticleID)
{
    try
    {

        PagerControl1.PageSize = 4;
        //PagerControl1.TotalItems = 1;
        //PagerControl1.PageMode = 4;
        PagerControl1.DisplayEntriesCount = 5;
        //Will show 2 links after ...
        PagerControl1.EdgeEntriesCount = 0;
        DataSet ds = DataProvider.GetCommentList(iArticleID);
        DataView dv = ds.Tables[0].DefaultView;

        //pass the datatable and control to bind
        PagerControl1.BindDataWithPaging(rptCommentList, dv.Table);

    }
    catch (Exception ex)
    {
        HttpContext.Current.Response.Redirect("Message.aspx?msg=Invalid Request");
    }

Answer 1

The problem isn't with UpdatePanel, but with the Repeater. Controls inside the update panel can be directly accessed within the scope of the page (such as the repeater itself), whilst controls within the repeater have to be "found" during or after they have been bound. Your code within the repeater is a template for many items and not specific to any one.

I'd suggest adding an ItemDataBound event to your repeater and perform the logic inside this event as each item is being bound to the repeater.

<asp:Repeater ID="rptCommentList" runat="server" EnableViewState="false"
     OnItemDataBound="rptCommentList_ItemDataBound">

 

protected void rptCommentList_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) 
    {
        // get the data item
        MyObject myObject = (MyObject)e.Item.DataItem;

        // find the label
        Label lblComUserName = (Label)e.Item.FindControl("lblComUserName");

        // do the magic!
        if (myObject.comAnonymous)
             lblComUserName.Visible = false;
    }
}

Obviously, replace MyObject with the object type of the collection/list/table you are binding to the repeater in the first place.

Hope that helps.

Answer 2

If the control is inside the repeater

 Label lbl=(Label)Repeater1.FindControl("lbl1");

should do the job. Otherwise you can directly access the controls. If not the page has errors and not compiling