C# – WebBrowser control: how to suppress message: do you want to close this window

As per Prerak K's update comment (since deleted):

I guess I have not presented the question properly.

Situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.

So only accessing the value so that corresponding data can be fetched from the database.

The solution you want then should look like:

UserContrl1_LOadDataMethod()
{
    string name = "";
    if(textbox1.InvokeRequired)
    {
        textbox1.Invoke(new MethodInvoker(delegate { name = textbox1.text; }));
    }
    if(name == "MyName")
    {
        // do whatever
    }
}

Do your serious processing in the separate thread before you attempt to switch back to the control's thread. For example:

UserContrl1_LOadDataMethod()
{
    if(textbox1.text=="MyName") //<<======Now it wont give exception**
    {
        //Load data correspondin to "MyName"
        //Populate a globale variable List<string> which will be
        //bound to grid at some later stage
        if(InvokeRequired)
        {
            // after we've done all the processing, 
            this.Invoke(new MethodInvoker(delegate {
                // load the control with the appropriate data
            }));
            return;
        }
    }
}

Yes, there is way to pass the Window.Opener object from one WebBrowser control to the next.
See code below for details.

public class WebBrowserTest
{
    private WebBrowser _wParent;

    // entry point
    public void Navigate(string url)
    {
        _wParent = new WebBrowser();
        SHDocVw.WebBrowser_V1 v1 = (SHDocVw.WebBrowser_V1)w.ActiveXInstance;
        v1.NewWindow += v1_NewWindow;
    }

    private void v1_NewWindow(string URL, int Flags, string TargetFrameName, ref object PostData, string Headers, ref bool Processed)
    {
        // tell, that we'll open new page by ourselves
        Processed = true;

        // open page by ourselves
        WebBrowser w2 = new WebBrowser();
        w2.Navigate(url);

        // wait for document will be loaded to do some magic stuff then
        w2.DocumentCompleted += w2_DocumentCompleted;
    }

    // sets opener for popup window
    // after document in popup window was loaded
    private void w2_DocumentCompleted(object sender, EventArgs e)
    {
        WebBrowser popup = (WebBrowser)sender;
        SetOpener(_wparent, popup);
    }

    // My most favorite method :)
    // Contains exactly that hack, we're talking about
    private void SetOpener(WebBrowser opener, WebBrowser popup)
    {    
        HtmlWindow htmlPopup = popup.Document.Window;
        HtmlWindow htmlOpener = opener.Document.Window;

        // let the dark magic begin

        // actually, WebBrowser control is .NET wrapper around IE COM interfaces
        // we can get a bit closer to them access by getting reference to 
        // "mshtml.IHTMLWindow2" field via Reflection
        FieldInfo fi = htmlPopup.GetType().GetField("htmlWindow2", BindingFlags.Instance | BindingFlags.NonPublic);

        mshtml.IHTMLWindow2 htmlPopup2 = (mshtml.IHTMLWindow2)fi.GetValue(htmlPopup);
        mshtml.IHTMLWindow2 htmlOpener2 = (mshtml.IHTMLWindow2)fi.GetValue(htmlOpener);

        // opener is set here
        htmlPopup2.window.opener = htmlOpener2.window.self;
    }
}

p.s. I understand, chances, that it's still actual, are very small, but, anyway =)