LayeredWindow 构造函数

public LayeredWindow(
	Bitmap bmp,
	bool keepBmp = false
)

Public Sub New ( 
	bmp As Bitmap,
	Optional keepBmp As Boolean = false
)

new : 
        bmp : Bitmap * 
        ?keepBmp : bool 
(* Defaults:
        let _keepBmp = defaultArg keepBmp false
*)
-> LayeredWindow