Graphics.DrawImage ( _
image As Image, _
destRect As Rectangle, _
srcX As Integer, _
srcY As Integer, _
srcWidth As Integer, _
srcHeight As Integer, _
srcUnit As GraphicsUnit, _
imageAttr As ImageAttributes _
)
ImageAttributes有個成員方法.SetColorKey (Color, Color) ,可以設置透明色範圍.如果妳要做漸變透明也可以修改其他屬性.比如使用顏色替換,背景色替換成半透明色