How do i access controls under the update progress or update panel.
I have 1 Update progress then i want to access the label inside the update progess. I want to change the text property of the label when my edit image button allter it. thanks
You will need to find the control recursively. However, the FindControl method will not find controls recursviely. Use this cool method FindControlRecursive(Control root, string id) by Jeff Atwood. The reason you cant access them otherwise is because they are child controls. Visit Jeff Atwoods article athttp://www.codinghorror.com/blog/archives/000307.html I use that to find controls. Once you find the control you will need to cast it to the type of control it is. Example:
TextBox tb = (TextBox)FindControlRecursive(Page,"txtNameOfControl");
tb.Text ="Hello there";
The above is an example as if you were finding a textbox.
Let me know if you need more help!
John
hello.
well, yes and no. for updatepanels, you don't need to use findcontrol since the controls are injected on the page as fields (which means you can simply use its id to get a reference to them)
regarding the updateprogress, things get a little messy. here's an example that shows how to change it during a full postback:
<%@. Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void E(Object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2000);
}
private Boolean update = false;
void J(Object sender, EventArgs e)
{
update = true;
}
protected override void Render(HtmlTextWriter writer)
{
if (update)
{
Label lbl = (Label) progress.FindControl("lbl");
lbl.Text = DateTime.Now.ToString();
}
base.Render(writer);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel runat="server" ID="panel">
<ContentTemplate>
<asp:Button runat="server" id="bt" text="partial postback" OnClick="E"/>
</ContentTemplate>
</asp:UpdatePanel>
<asp:Button runat="server" text="full postback" OnClick="J" />
<asp:UpdateProgress runat="server" ID="progress" AssociatedUpdatePanelID="panel">
<ProgressTemplate>
<asp:Label runat="server" id="lbl" />
</ProgressTemplate>
</asp:UpdateProgress>
</form>
</body>
</html>
Acutally I am trying to recall my orginal issue and why I used FindControlRecurvively and I beleive it was because I had a Drop Down List in a custom server control which was in an tab panel. The version of Ajax.net at the time had an issue with doing that and it throwing a null reference. This was some months ago so I don't recall all the logistics:
If you use FindControl to access a control inside a TabPanel, it throws a NullReferenceException.This behavior appears in the 10606 release10301. If you compile the same application with the March release (10301) it works well.
http://www.codeplex.com/AtlasControlToolkit/WorkItem/View.aspx?WorkItemId=11168
hello again.
ok, fair enough. but regarding the controls you've asked about (updatepanel and udpateprogress) my previous observations are correct.
Thanks for the reply, it works I've just create a new instance of label then assign the findcontrol to it.
dim lbl as label
lbl = updatepanel1.findcontrol("label1")
lbl.text = "hello"
thanks
hello again.
hum...why are you doing that? I mean, the controls declared inside an updatepanel are also inserted on the page as fields so you can only use its id to get them (this is not true for controls that are inside an updateprogress control)
Thanks for concern, I try it but it does not work, for example i have label1 inside the updatepanel1. So how do i access the label1 and change the text property?
Can you teach me how... Thanks again...
hello.
well, you just use its id:
label1.Text = "something";
do keep in mind that this code will only work if you're using it frmo the same page or user control that has the updatepanel which has the label inside...
Dim pwdAs ChangePasswordpwd = updatePanel1.FindControl("ChangePassword1")
pwd.Visible =True
This worked for me too, thanks guys.
Sasanka Pinidiya
Xiyuan Shen: