Doing UI Work in the background

What's the simplest way to do background work with the UI and also know when it has 开发者_如何学JAVAended?

Try a backgroundworker

http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

I guess that you would benefit from Threading in C#, part 3 by Joseph Albahari. Especially the section "Subclassing BackgroundWorker" should be useful.