在VS210中使用ContexMenu时，在xmal中智能提示的错误，不知道怎么回事？
The property 'ContextMenu' does not exist on the type 'ListBox' in the XML namespace 'https://schemas.microsoft.com/winfx/2006/xaml/presentation'. C:\Users\cnpc\Documents\Visual Studio 2010\Projects\SudanMap\SudanMap\MainPage.xaml
The property 'ContextMenu' does not exist on the type 'ListBox' in the XML namespace 'https://schemas.microsoft.com/winfx/2006/xaml/presentation'. C:\Users\cnpc\Documents\Visual Studio 2010\Projects\SudanMap\SudanMap\MainPage.xaml
