SendMessage only works once on same object

[jmsrickland]

I have two apps, App1 and App2. App1 has the HWND of App2's Command1 button. In App1 I have this code:


App1 Code

Private Sub Command1_Click()
 If Command1.Caption = "Start" Then
   Command1.Caption = "Stop"
   SetForegroundWindow App2Command1Hwnd
   SendMessageByString App2Command1Hwnd, BM_CLICK, 0, 0
 Else
   Command2.Caption = "Start"
   SetForegroundWindow App2Command1Hwnd
   SendMessageByString App2Command1Hwnd, BM_CLICK, 0, 0
  End If
End Sub

The first time I click on Command1 in App1 it sends the BM_CLICK to App2's Command1 and clicks it. Code under Start in App2 runs

The second time I click on Command1 in App1 nothing changes in App2's Command1 click event. Processing continues; does not stop. Actually the button is not fired at all because I have MsgBoxes telling me where control is. First time MsgBox prints "Inside If", second time no message is displayed where I thought it would have been "Inside Else".

App2's Form gets the Focus on both times I click on App1's Command1 button

App2 Code

Private Sub Command1_Click()
 If Command1.Caption = "Start" Then
   '
   ' ENTERS HERE
   '
   MsgBox "Inside If"
   Command1.Caption = "Stop"
 Else
   '
   ' NEVER ENTERS HERE
   '
   MsgBox "Inside Else"
   Command1.Caption = "Start"
 End If
End Sub