'Declaration
Protected Overridable Function GetRotateAngle( _
ByVal centerPt As Point, _
ByVal pt1 As Point, _
ByVal pt2 As Point _
) As Single
'使用法
Dim instance As PSObject
Dim centerPt As Point
Dim pt1 As Point
Dim pt2 As Point
Dim value As Single
value = instance.GetRotateAngle(centerPt, pt1, pt2)