How can I access an IFRAME from the codebehind file in ASP.NET?

Question

I am trying to set attributes for an IFRAME html control from the code-behind aspx.cs file.

I came across a post that says you can use FindControl to find the non-asp controls using:

The aspx file contains:

<iframe id="contentPanel1" runat="server" /> 

and then the code-behind file contains:

protected void Page_Load(object sender, EventArgs e) {     HtmlControl contentPanel1 = (HtmlControl)this.FindControl("contentPanel1");     if (contentPanel1 != null)         contentPanel1.Attributes["src"] = "http://www.stackoverflow.com";  } 

Except that it's not finding the control, contentPanel1 is null.

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Update 1

Looking at the rendered html:

<iframe id="ctl00_ContentPlaceHolder1_contentPanel1"></iframe> 

i tried changing the code-behind to:

HtmlControl contentPanel1 = (HtmlControl)this.FindControl("ctl00_ContentPlaceHolder1_contentPanel1");  if (contentPanel1 != null)     contentPanel1.Attributes["src"] = "http://www.clis.com"; 

But it didn't help.

i am using a MasterPage.

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Update 2

Changing the aspx file to:

<iframe id="contentPanel1" name="contentPanel1" runat="server" /> 

also didn't help

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Answer

The answer is obvious, and unworthy of even asking the original question. If you have the aspx code:

<iframe id="contentPanel1" runat="server" /> 

and want to access the iframe from the code-behind file, you just access it:

this.contentPanel1.Attributes["src"] = "http://www.stackoverflow.com"; 

Answer 1

This works for me.

ASPX :

<iframe id="ContentIframe" runat="server"></iframe> 

I can access the iframe directly via id.

Code Behind :

ContentIframe.Attributes["src"] = "stackoverflow.com"; 

Answer 2

If the iframe is directly on the page where the code is running, you should be able to reference it directly:

 contentPanel1.Attribute = value; 

If not (it's in a child control, or the MasterPage), you'll need a good idea of the hierarchy of the page... Or use the brute-force method of writing a recursive version of FindControl().