Can't seem to use focus() on my textbox

[tshad]

I have tried to set focus to a textbox in my DataList Footer section which has a textbox and I get a null exception for some reason.

The FooterTemplate looks like:

<FooterTemplate>
    <asp:Panel ID="newQuestionPanel" Visible="false" runat="server">
		<table border="0" cellpadding="0" cellspacing="0">
			<tr>
				<td width="100%">
                  	<asp:TextBox ID="newQuestion" Columns="80" runat="server" />&nbsp;
				<td>
                    <asp:LinkButton CommandName="AddQuestion" CssClass="vertical-align:top" 
                        Text="<img src='..\..\images\addButton.gif'border='0'>" 
                        ID="btnAdd" runat="server" />            
				</td>
			</tr>
		</table>
    </asp:Panel>
    <asp:Button ID="AddQuestion" Text="Add Question" runat="server" 
        CommandName="AddRow" CommandArgument="AddRow"></asp:Button>
</FooterTemplate>

The following code comes from the DataListItemCreated event

public void DataList_ItemCreated(object Sender, DataListItemEventArgs e)
{
    switch (e.Item.ItemType)
    {
        case ListItemType.Footer:
            if (ShowQuestion)
            {
                ShowQuestionPanel((Panel)e.Item.FindControl("newQuestionPanel"));
            }
            break;
    }
}

This is the ShowQuestionPanel called from the above call and works fine except for the Focus() method.

        private void ShowQuestionPanel(Panel panel)
        {
            TextBox textbox;

            ((Button)(panel.FindControl("AddQuestion"))).Text = "Close Question";
            // ((TextBox)(panel.FindControl("NewQuestion"))).Focus();
            textbox = (TextBox)panel.FindControl("NewQuestion");

            textbox.Text = "toms test";
            //textbox.Focus();

        }

From the watch window.

textbox.Focus()	'textbox.Focus()' threw an exception of type 'System.NullReferenceException'
textbox.Text	"toms test"

So why can I set the Text but I can't set the focus to the Textbox???
Why is it a SystemNullReferenceException

I originally tried to do it in one statement (which is commented out above and also got the System.NullReferenceException.

But the following works as it does when I create the Textbox explicitly:

((TextBox)(panel.FindControl("NewQuestion"))).Text

Why doesn't this work?

Thanks,

Tom

 

[tshad]

Also, when I press the button, this seems to work:

((TextBox)(((Button)e.CommandSource).Parent.FindControl("NewQuestion"))).Focus();

So not sure why the other code doesn't.

Tom

 

[tshad]

I found out that if the program "ShowQuestionPanel", is called from: DataList_ItemCreated - it doesn't work (the Focus() get the error).

If the same method is called from: DataList_ItemCommand - it does work.

Not sure why it works in one but not the other.

In both cases, I can do:

textbox = (TextBox)panel.FindControl("NewQuestion");
textbox.Text = "toms test";

Thanks,

Tom

 

[jbenson001]

Again, this is where the ItemDataBound event could be used.

 

[tshad]

Fine.

But the question is why doesn't this work?

Thanks,

Tom

 

[jbenson001]

I'm not sure if this matters, but in your code you have "NewQuestion", but the control name in the markup "newQuestion"
Not sure if the case would somehow make a difference.

As far as your code is, it should work. I looked up on MSDN about the ItemCreated event and you should have access to the controls per their examples.

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.datalist.itemcreated.aspx

 

[tshad]

But access isn't the problem as you can see, I do have access. I can set the .Text property. But I get an error with the .Focus.

But I only have the problem in the DataList_ItemCreated but not in the DataList_ItemCommand.

Thanks,

Tom