C#: Simple thread

thread.cs

new Thread(delegate()
{
    Dispatcher.BeginInvoke(new Action(delegate()
    {
        // Do something in the "main" thread (the thread calling the new thread).
    }));

    // Do whatever you want.
    Thread.Sleep(3000);

    Dispatcher.BeginInvoke(new Action(delegate()
    {
        // Do something else in the "main" thread.
    }));

}).Start();