WPF Background Worker | Tech Off

vesuvius
Das Glasperlenspiel

Is there a way to achive multi-threading with the ease and elegance that the BackgroundWorker does in Windows Forms?

Dexter

Well, of course, you use the BackgroundWorker! It's not Windows Forms specific.

vesuvius
Das Glasperlenspiel

In reply to Dexter

#May 11th @ 12:37 AM

I am a little confused. Why then have they created a DispatcherTimer when .NET already has three pretty flexible timers? (well two really, as the windows forms component is a waste of time - pun intended)

I know that they use the background worker in Silverlight, which I guess is great, as it's less for me to learn.

Dexter

In reply to vesuvius

#May 11th @ 1:38 AM

I'm not sure what timers have to do with BackgroundWorker.

The DispatcherTimer is basically the equivalent of the WinForms timer. The WinForms timer is implemented using the Win32 message loop and WM_TIMER messages and the DispatcherTimer is implemented using the WPF Dispatcher (which broadly speaking is the equivalent to the Win32 message loop).

The other 2 timers that I know of invoke the "tick" callback on a different thread than the UI thread, they're not aware of SynchronizationContext(s) like BackgroundWorker is.

vesuvius
Das Glasperlenspiel

What I meant was why did they not create a DispatcherBackgroundWorker?

To be honest I did try the DispatcherTimer and was nonplussed with its accuracy, but I thought is was my code and lack of understanding of WPF. Your explanation is timely.

I will just use the backgroundworker then.

Dexter

In reply to vesuvius

#May 11th @ 2:44 AM

What would a DispatcherBackgroundWorker do? The dispatcher is associated with a thread. Would that mean that a DispacthedBackgroundWorker is associated with that tread too? Then it wouldn't be "background" anymore.

They did create a DispatcherSynchronizationContext which enables the BackgroundWorker to forward calls from the backgound thread to the UI thread. Just like the WindowsFormsSynchronizationContext does.