Can I detect errors while using a .Net WebBrowser

Question

I have an .Net Froms application that displays web pages through a WebBrowser control.

Is there anyway that I can detect if the control shows a 'Page not found' or 'Cannot display webpage' error? There doesn't seem to be any error event handlers.

Answer 1

The WebBrowser windows forms control is wrapper around Internet Explorer and it doesn't expose all the functionality of the underlying ActiveX control and particularly the NavigateError event. Here's a workaround:

First add reference to SHDocVw.dll to your project (COM tab of Add Reference window). Then you can do the following to capture errors:

private void button1_Click(object sender, EventArgs e)
{
    SHDocVw.WebBrowser instance = (SHDocVw.WebBrowser)webBrowser1.ActiveXInstance;
    instance.NavigateError += new SHDocVw.DWebBrowserEvents2_NavigateErrorEventHandler(instance_NavigateError);
    webBrowser1.Navigate("http://www.google.com/foo");
}

void instance_NavigateError(object pDisp, ref object URL, ref object Frame, ref object StatusCode, ref bool Cancel)
{
    // Do whatever you want with the error            
}

Answer 2

I found another way to solve this without setting a reference to the SHDocVw dll.

See web browser CreateSink method on MSDN.