Tab with OnKeyDown

Most of the time the tab key is handled by Windows and your program
doesn't see it. There are couple of ways to go about getting at the tab key,
both involve responding to Windows messages. Have a look at the links below:

http://www.temporaldoorway.com/programming/cbuilder/advancedissue/oddkeys.htm 
And
http://www.bcbdev.com/faqs/faq78.htm 

void OnKeyDown( UINT nChar, UINT nRepCnt, UINT nFlags)
{
   if  (nChar == VK_TAB) //for the tab key
      //do your work

    //call the base class
     CWnd::OnKeyDown(nChar,nRepCnt,nFlags);
}

sniipet from http://www.bcbdev.com/faqs/faq78.htm 
...
To receive key events for the TAB key, the focused cotnrol must return DLGC_WANTTAB. To receive key events for the arrow keys, return DLGC_WANTARROWS. If you want to receive events for both the arrow keys and the TAB key, then bitwise OR DLGC_WANTARROWS with DLGC_WANTTAB and return that value. If you want to receive key events for all keys, then return DLGC_WANTALLKEYS.

The VCL contains some good examples of how to use the WM_GETDLGCODE message. TToolBar responds to WM_GETDLGCODE so it can receive events for the arrow keys, and TCustomGrid uses WM_GETDLGCODE to request both the arrow keys and the TAB key. TMediaPlayer and TDBNavigator use WM_GETDLGCODE to request the arrow keys. Here are some code snippets from the VCL that demonstrate how they respond to the WM_GETDLGCODE message. I have converted code from pascal to C++ for readability.

void __fastcall TToolBar::WMGetDlgCode(TMessage & Message)
{
    // only want the arrow keys in some situations
    if(FInMenuLoop)
        Message.Result = DLGC_WANTARROWS;
}

void __fastcall TCustomGrid::WMGetDlgCode(TMessage & Message)
{
    // always want the arrow keys
    Msg.Result := DLGC_WANTARROWS;
    ...

    // sometimes want the tab key
    if (Options.Contains(goTabs))
        Msg.Result |= DLGC_WANTTAB;

    // sometimes want WM_CHAR messages
    if (Options.Contains(goEditing))
        Msg.Result |= DLGC_WANTCHARS;
}

void __fastcall TMediaPlayer::WMGetDlgCode(TMessage &Message)
{
    Message.Result = DLGC_WANTARROWS;
}

Note: Don't create a WM_GETDLGCODE handler for your form. You must write the WM_GETDLGCODE handler at the control level.

Note: In VCL programs, the operating system is not actually the creator of the WM_GETDLGCODE message. The VCL synthesizes the message. Fortunately, this is an implementation detail that you can ignore. Simply write your WM_GETDLGCODE handler as if the OS was the creator of the message.
...
I hope, it helps. Alex

 

Yes, I've read that before, but isn't that only for capturing tab in different components and not directly on a form? The note sais not to create a WM_GETDLGCODE handler for your form. This doesn't seem to work:

void __fastcall TForm::WMGetDlgCode(TMessage &Message)
{
   Message.Result = DLGC_WANTTAB;
}

Great, thanks!