C＃图片框

Question

I am having a problem with adding some picture boxes . I have a form (and it's class) and a separate class. What i want to do is to put some picture boxes from my second class in the form , but it seems I just can't figure out how. Oh, and I don't want to send the picture box from the second class to the main one, and add it there, but just add it directly. If I try something like:

Form1.ActiveForm.Controls.Add(x); 

(where x is my picture box) from the second class I get 'Cross-thread operation not valid' exception.

Thanks for any advices!

Answer 1

Are you trying to run show your picture on a non-UI thread? Usually this is how you get a cross-thread operation not valid exception.

You may simple need to do something like the following in your class.

if (this.InvokeRequired)
{
   this.Invoke(() => ActiveForm.Controls.Add(x));
}
else
{
   ActiveForm.Controls.Add(x);
}

This will ensure you are using the UI thread to execute your code.