成员的完整列表，这些成员属于 sw::MouseButtonDownEventArgs,包括所有继承而来的类成员

EventType	sw::TypedRoutedEventArgs< UIElement_MouseButtonDown >	static
eventType	sw::RoutedEventArgs
handled	sw::RoutedEventArgs
handledMsg	sw::RoutedEventArgs
key (定义于 sw::MouseButtonDownEventArgs)	sw::MouseButtonDownEventArgs
keyState (定义于 sw::MouseButtonDownEventArgs)	sw::MouseButtonDownEventArgs
MouseButtonDownEventArgs(MouseKey key, Point mousePosition, MouseKey keyState) (定义于 sw::MouseButtonDownEventArgs)	sw::MouseButtonDownEventArgs	inline
mousePosition (定义于 sw::MouseButtonDownEventArgs)	sw::MouseButtonDownEventArgs
originalSource	sw::RoutedEventArgs
RoutedEventArgs(RoutedEventType eventType)	sw::RoutedEventArgs
source	sw::RoutedEventArgs
TypedRoutedEventArgs()	sw::TypedRoutedEventArgs< UIElement_MouseButtonDown >	inline