Question

I want to detect when the right shift key is released on a form in VB6. I have the following code:

Private Declare Function GetKeyState Lib "user32" (ByVal nVirtKey As Long) As Integer

Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer)
    If GetKeyState(VK_RSHIFT) < 0 Then
        MsgBox "Right Shift Released"
    End If
End Sub

Except, it doesn’t work. By the time the event is fired the key has been released and the GetKeyState API function returns 0.

What’s the solution?

Answer 1

The Shift parameter tells you what combination of Shift, Ctrl, and Alt keys are down. It doesn’t distinguish between left and right, though. For that, you have to use the GetKeyState API function.

Trap the right shift key when it goes down with similar code to what you have, but in the Form_KeyDown event. Set a module-level boolean to indicate that the key is now down. (Note that you’ll have to check that KeyCode is 16, which you’ll get for either shift key.)

Then, in the Form_KeyUp event, if your boolean says the key is down, but GetKeyState returns a negative number indicating that it’s actually up, you know the key has been released. Make sure you reset the form-level boolean at this time as well.