How to style the thumb of wpf slider?

I read about style here:

http://msdn.microsoft.com/en-us/library/cc278073(v=VS.95).aspx

I created a UserControl with slider and UserControl.Resources section. I paste 开发者_如何学Gothe thumb style but some tag are not recognized like vsm:VisualStateManager (I'm using VS2010) why ?

That is the documentation for Silverlight. You probably want the documentation for WPF:

• Slider Styles and Templates

Edit:

Just to be clear, if you are using Silverlight, you should use Silverlight templates and styles; if you are using WPF, you should use WPF templates and styles.

In any case, the VisualStateManager is a full-fledged part of both Silverlight4 and WPF4, so if you see a template with the "vsm:" namespace, the simplest option is to just remove the prefix where-ever you see it.