Posting a Tab

[bushmobile]

this code sends 2 Tabs when it should only send one, shouldn't it?

Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" ( _
    ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
 
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" ( _
    ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
 
Private Const WM_KEYDOWN = &H100
Private Const WM_KEYUP = &H101
 
Private Sub Command1_Click()
    Dim lhWnd As Long
    
    lhWnd = FindWindowEx(FindWindowEx(0&, 0&, "notepad", vbNullString), 0&, "Edit", vbNullString)
    PostMessage lhWnd, WM_KEYDOWN, vbKeyTab, 1&
    PostMessage lhWnd, WM_KEYUP, vbKeyTab, 1&
End Sub

both WM_KEYDOWN and WM_KEYUP are causing a tab to be fired.

Should I be expecting this? I'm tired and confused...

[msayed2004]

PostMessage lhWnd, WM_KEYDOWN, vbKeyTab, 1&

Post a tab

PostMessage lhWnd, WM_KEYUP, vbKeyTab, 1&

post another one.

Why you need both ???

[Harsh Gupta]

Because you are posting a message and not invoking a keyboard stroke, so you dont need to set the UP message. I think you are doing it like keybd_event API.

When you post a message, the API will return back without waiting for the client thread to process the message. So your app thinks that you are posting the same message twice.

Sorry if I am wrong, but wait....

The PostMessage function places (posts) a message in the message queue associated with the thread that created the specified window and then returns without waiting for the thread to process the message.

I think I am quite close.

[bushmobile]

i forgot about this thread.

it seemed that both the WM_KEYDOWN and the WM_KEYUP message were triggering a WM_CHAR message - but sure why, maybe because I hadn't set the 30th bit of the WM_KEYUP lParam (haven't checked). Anyway - i just decided to send the WM_CHAR message instead.

Regarding PostMessage, that just sticks the message in the queue and it gets processed when it reaches the top - when you use the keyboard normally the messages are posted not sent (i believe) - so that's probably not the cause