public void SetMediaElement() { MediaElement media = new MediaElement(); VideoBrush brush = new VideoBrush(); object retval; brush.SourceName = "iTube"; media.Name = "YouTube"; brush.SetSource(media); Assert.AreEqual(String.Empty, brush.SourceName, "SourceName after SetSource"); // since String.Empty is the default value, we also have to check RLV retval = brush.ReadLocalValue(VideoBrush.SourceNameProperty); Assert.AreNotEqual(DependencyProperty.UnsetValue, retval, "SourceName is not cleared after SetSource"); }