WPF 滑鼠移動事件

假設已經動態產生以下物件，並指定事件
'設定當滑鼠指標移入 Ellipse 物件上方時所要執行的事件處理常式。

AddHandler Elp.MouseLeftButtonDown, AddressOf Elp_MouseDown
AddHandler Elp.MouseMove, AddressOf Elp_MouseMove
AddHandler Elp.MouseLeftButtonUp, AddressOf Elp_MouseUP


滑鼠事件： 按下
'-----------------------------
Private Sub Elp_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)

gloOriPos = e.GetPosition(Me.MYCS) '對哪一個物件取座標位置!
'偵測來源 sender 物件 並進行轉換
Select Case sender.GetType.ToString
Case "System.Windows.Shapes.Ellipse"
Dim Selobj As Ellipse = TryCast(sender, Ellipse)
gloSelObjName = Selobj.Name
Dim idx As Integer = 2
'改變顏色
Selobj.Fill = New SolidColorBrush(Color.FromRgb(ToRGB(idx).R, ToRGB(idx).G, ToRGB(idx).B))

'********** 以目前選取的物件 補捉滑鼠 ********** 這裡很重要
Selobj.CaptureMouse()

Case "System.Windows.Controls.TextBlock"
End Select

End Sub

滑鼠事件：　移動
'-----------------------------
Private Sub Elp_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)

'偵測滑鼠左鍵是否仍然被按下
If e.LeftButton = MouseButtonState.Pressed Then

Dim NowPos As Point ' = e.GetPosition(Me.MYCS) '對哪一個物件取座標位置!
NowPos = e.GetPosition(Me.MYCS)

'滑鼠 移動量()
Dim dx As Double = NowPos.X - gloOriPos.X
Dim dy As Double = NowPos.Y - gloOriPos.Y

'Me.Title = e.GetPosition(Me.MYCS).X & "," & e.GetPosition(Me.MYCS).Y

'偵測來源物件並轉型
Select Case sender.GetType.ToString
Case "System.Windows.Shapes.Ellipse"

Dim Selobj As Ellipse = TryCast(sender, Ellipse)

Canvas.SetLeft(Selobj, NowPos.X - (gloEllipseWidth / 2))
Canvas.SetTop(Selobj, NowPos.Y - (gloEllipseWidth / 2))
gloSelObjName = Selobj.Name

'呼叫移動線段的程式碼（假設該目標有好幾個線段連結）
Call LineMove("EL", Selobj)


Case "System.Windows.Controls.TextBlock"

End Select
'紀錄上次的位置
gloOriPos.X = NowPos.X
gloOriPos.Y = NowPos.Y

End If
　　
End Sub



滑鼠事件：放開
'-----------------------------
Private Sub Elp_MouseUP(ByVal sender As Object, ByVal e As MouseEventArgs)
'偵測來源物件並進行轉型
Select Case sender.GetType.ToString
Case "System.Windows.Shapes.Ellipse"
Dim Selobj As Ellipse = TryCast(sender, Ellipse)
gloSelObjName = Selobj.Name
'釋放滑鼠事件
Selobj.ReleaseMouseCapture()
'恢復原來的顏色
Dim idx As Integer = 1
Selobj.Fill = New SolidColorBrush(Color.FromRgb(ToRGB(idx).R, ToRGB(idx).G, ToRGB(idx).B))

Case "System.Windows.Controls.TextBlock"

End Select

End Sub