PlatformUI 命名空间参考

类
class	ISnapHandle
class	ISnapper
class	ISnapProcessedBase

枚举
enum class	SnapMode {   None = 0x0000 , Endpoint = 0x0001 , Midpoint = 0x0002 , Center = 0x0004 ,   Intersection = 0x0008 , All = 0xFFFF }