<toolkit:GestureListener DragDelta="taskitem_DragDelta" DragCompleted="taskitem_DragCompleted"/>
The code above always shows an error in Blend4, "Invalid XAML"
but never shows an error in VS2010 for WP.
and the app can run like a charm.
Why does this error happen and how I can solve it? is it just a bug?
Silverlight Toolkit just don't get along with Expression Blend nicely. I think there is some assembly version issues with the gesture event handler in the toolkit, but unless they update it, there's nothing you could do. The way I get around this problem is by collapsing the control that has toolkit items when I'm doing layout work, and enabling them again afterwards. Or edit it using the designer in VS