Threading and webbrowser control

问题

I'm very new to threading. I start a thread like this:

Thread t_main;
t_main = new Thread(main_building_stuff);
t_main.Start();

And at some point, I want in the main_building_stuff to grap some data from an webpage that is loaded into an webbrowser controll in the main thread.

I'm doing that with this piece of code:

HtmlElement lit = webBrowser1.Document.GetElementById("buildqueue");

But that results in an error... InvalidCastException (specified cast is not valid)

What is the proper way to receive the data from the webbrowser?

回答1:

Somebody that answerd the question, gave the right answer. But for some reason, he deleted it, so thank you, but i don't remember your name...

This was the piece of code that worked:

webBrowser1.Invoke(new Action(() => {
                    HtmlElement lit = webBrowser1.Document.GetElementById("buildqueue");
                    result = "whatever";
                }));

回答2:

Hmmm.

System.Windows.Forms.HtmlDocument.GetElementById() definitely returns a System.Windows.Forms.HtmlElement.

What happens if you change

HtmlElement lit = webBrowser1.Document.GetElementById("buildqueue");

System.Windows.Forms.HtmlElement lit = webBrowser1.Document.GetElementById("buildqueue");

Do you still get an invalid cast error?

I just happen to know that there are multiple commonly used classes called HtmlElement and I wonder if you've got one from another namespace imported.

来源：https://stackoverflow.com/questions/12386071/threading-and-webbrowser-control

标签

multithreading

thread-safety

webbrowser-control