Question

Hey guys, I’m getting a really strange error. I have a program that needs to run a thread on startup, and for some reason when I do myThread.Start() in Form1() it will crash with “program is not working” (But only on Windows Server, not on my local machine!). However, if I put the same code under button1_Start() it works no problem. What gives?

Any ideas?
Thank you.

EDIT
A little extra information: In my thread I have a line of code that uses invoke

Invoke(new Action(() => richTextBox1.AppendText(string.Format("Updating {0}..\n", DateTime.Now))));

And for some reason the crashing goes away after I make the thread sleep for 2 seconds before it starts executing. Am I using the right method to execute code on the app startup?

Answer 1

Note, this is a guess, you haven’t given nearly enough information in your question to give you any definitive answers.

I doubt it has anything to do with Windows Server 2008, but probably more with the fact that the server has more CPU cores and/or a faster processor than your development machine.

If you, in the thread tries to either access the form through a variable, or you try to invoke back to the thread that owns the form, you will crash on a fast computer.

Why?

In the first case, the variable has not yet been set. The following code:

var fm = new Form1();

here, fm will not be set before the constructor has returned. If your thread has already tried to access the form through fm, that variable is null.

In the second case, the constructor is not responsible for showing the form, that happens afterwards. Many controls postpone actually allocating a handle until they are asked to draw themselves, and thus if the thread tries to do stuff to a control before that, it will crash.

You should instead start your thread from Form_Load.