获取鼠标在画布上的位置（但不在窗口上）？

Point p = Mouse.GetPosition(canvas);

<DebuggerHidden> _
<System.Runtime.CompilerServices.Extension> _
Public Function toWfpPoint(p As System.Drawing.Point) As Point
    Return new Point(p.X, p.Y)
End Function

Dim MousPos As Point = System.Windows.Forms.Control.MousePosition.toWfpPoint