How do I refresh visual control properties (TextBlock.text) set inside a loop?

With each loop iteration, I want to visually update the text of a textblock. My problem is that the WPF window or control does not visually refresh until the loop is complete.

for (int i = 0; i < 50; i++)
{
    System.Threading.Thread.Sleep(100);
    myTextBlock.Text = i.ToString();                
}

In VB6, I would call DoEvents() or control.Refresh. At the moment I'd just like a quick and dirty solution similar to DoEvents(), but I'd also like to know about alternatives or the "right" way to do this. Is there a simple binding statement I could add? What is the syntax? Thanks in advance.