我們都知道,在.Net的鼠標事件中判斷鼠標事件方法如下(以button為例):

Private Sub Button1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Button1.MouseDown
??????? If e.Button = Windows.Forms.MouseButtons.Left Then
??????????? MsgBox("left_mouse clicked")
??????? ElseIf e.Button = Windows.Forms.MouseButtons.Middle Then
??????????? MsgBox("middle_mouse clicked")
??????? ElseIf e.Button = Windows.Forms.MouseButtons.Right Then
??????????? MsgBox("right_mouse clicked")
??????? End If
End Sub

?

在ArcEngine的AxMapControl1_OnMouseDown事件中我也仿照以上方法判斷如下:

Private Sub AxMapControl1_OnMouseDown(ByVal sender As System.Object, ByVal e As ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent) Handles AxMapControl1.OnMouseDown

??????????If e.button = MouseButtons.Left? Then
??????????? MsgBox("left_mouse clicked")

??????????End If

Exit Sub

結果提示警告:"通過實例訪問共享成員，變量成員，枚舉成員或嵌套類型；將不計算限定表達式"

警告的意思大概就是:共享成員(就像C++中的靜態成員變量)不能通過實例訪問,而應該用類直接訪問

?

于是,修改如下:

Private Sub AxMapControl1_OnMouseDown(ByVal sender As System.Object, ByVal e As ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent) Handles AxMapControl1.OnMouseDown

??????????If e.button = Windows.Forms.MouseButtons.Left? Then
??????????? MsgBox("left_mouse clicked")

??????????End If

Exit Sub

結果仍然有問題:

于是,我在該事件中將用msgbox觀察e.button的數值到底是多少

結果按左鍵得到 1 , 按右鍵得到 2, 按中鍵得到 4 ,而非原先Windows.Forms.MouseButtons.Left(一個很大的六位數):

可見ArcEngine中鼠標事件中 鼠標按鍵判斷 從.Net鼠標事件中 鼠標按鍵判斷 繼承而來,但作了修改

?

好了,AreEngine中正確的鼠標按鍵判斷應該如下:

Private Sub AxMapControl1_OnMouseDown(ByVal sender As System.Object, ByVal e As ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent) Handles AxMapControl1.OnMouseDown

??????? If e.button = 1 Then
??????????? MsgBox("left_mouse clicked")
??????? ElseIf e.button = 2 Then
??????????? MsgBox("right_mouse clicked")
??????? ElseIf e.button = 4 Then
??????????? MsgBox("middle_mouse clicked")
??????? End If

Exit Sub

?

轉載于:https://www.cnblogs.com/ycbfish333/archive/2008/08/09/1264167.html

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