如何获取Max视图的左上角的屏幕位置

其实就是一个坐标转换 

Fn GetViewportRootPos  = Mouse.ScreenPos - Mouse.Pos
GetViewportRootPos()

try(DestroyDialog TestFollowViewport)catch()
Rollout TestFollowViewport "TestFollowViewport"
(
    Timer theTimer interval:100
    on theTimer tick do
    (
        SetDialogPos TestFollowViewport ( Mouse.ScreenPos - Mouse.Pos)
    )

)
CreateDialog TestFollowViewport