Question

I am working on a network application with threading. I have an event handler which results in a form showing on the screen. The problem is that the thread that makes this call blocks right after, so the form that shows blocks as well.

I have hacked this problem by making that function change something in the form it’s currently in, and then used invoke required to force the new form onto that thread. This is a terrible hack, what is the right way to make the new form.Show() method go through its own thread.

Note that I have tried just making a worker thread that runs only form.show() but the form disappears right after the call.

Thank you,

PM

Answer 1

You don’t want UI elements being created in their own threads. The primary thread that launched your application should be the UI thread. Create and show all elements on this thread. All your heavy, long-time or blocking work should be done on their own threads.

You can use BackgroundWorker to execute a single additional task without blocking your UI and get automatic synchronization when you need to make updates to the main (UI) thread such as to update progress bars or show a final result.

If you need multiple threads doing long-running work, use the ThreadPool. You will have to do your own cross-thread synchronization if you need to update UI elements. There are a ton of answers on how to do that already if that’s the route you go.

If you have multiple threads that are being blocked while waiting for something to happen, you should use threads yourself. This will keep the ThreadPool from being starved of threads because they are all blocking. (I believe this has been changed in .NET 4 so if you’re targeting that version you can probably easily continue using the ThreadPool in this situation.)