如何判断按下的Ctrl键是左边的还是右边的？

4楼和5楼都很好！
还有一个问题，如何向指定窗口发送类似与
LCtrl+RCtrl+小键盘Enter
的消息？
满意的话再加50分！

用api来判断...c#的话,也可以调用那个api...

用API （GetAsyncKeyState）实现键盘左右的shift,Ctrl或Alt键的判定，在WIN 2K，XP 下有效：
------------------------------------------------------------
Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
Private Const VK_LSHIFT = &HA0
Private Const VK_RSHIFT = &HA1
Private Const VK_LCTRL = &HA2
Private Const VK_RCTRL = &HA3
Private Const VK_LMENU = &HA4
Private Const VK_RMENU = &HA5

Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = vbKeyShift And Shift = vbShiftMask And (GetAsyncKeyState(VK_LSHIFT) And &H8000)
Then MsgBox "you click the Left Shift"
If KeyCode = vbKeyShift And Shift = vbShiftMask And (GetAsyncKeyState(VK_RSHIFT) And &H8000)
Then MsgBox "you click the RIGHT Shift"

If KeyCode = vbKeyMenu And Shift = vbAltMask And (GetAsyncKeyState(VK_LMENU) And &H8000)
Then MsgBox "you click the Left ALT" ' only ALT was pressed
If KeyCode = vbKeyMenu And Shift = vbAltMask And (GetAsyncKeyState(VK_RMENU) And &H8000)
Then MsgBox "you click the RIGHT ALT" ' only ALT was pressed

If KeyCode = vbKeyControl And Shift = vbCtrlMask And (GetAsyncKeyState(VK_LCTRL) And &H8000)
Then MsgBox "you click the Left CTRL"
If KeyCode = vbKeyControl And Shift = vbCtrlMask And (GetAsyncKeyState(VK_RCTRL) And &H8000)
Then MsgBox "you click the Right CTRL"

End Sub

Private Sub Form_Load()
Me.KeyPreview = True
End Sub

C#，控件的KeyDown事件 private void txtBarcode_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e) { if(e.KeyCode==Keys.LControlKey) { //左ctrl键 } //Keys.LControlKey; // //Keys.RControlKey; //右ctrl键 //Keys.LShiftKey; //左shift //Keys.RShiftKey; //右shift } 其他的可以通过 Keys枚举类型查找。

用左手就是左面

左手就是左边的右手也是右边的 娃哈哈阿

先检查你的电脑设置是否正常，然后检查键盘连接与键盘内部！

没办法