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 WM_GETDLGCODE

The WM_GETDLGCODE message is sent to the window procedure associated with a control. By default, the system handles all keyboard input to the control; the system interprets certain types of keyboard input as dialog box navigation keys. To override this default behavior, the control can respond to the WM_GETDLGCODE message to indicate the types of input it wants to process itself.

Syntax

    WM_GETDLGCODE
        WPARAM wParam
        LPARAM lParam;

Parameters

• wParam
  The virtual key, pressed by the user, that prompted Microsoft Windows to issue this notification. The handler must selectively handle these keys. For instance, the handler might accept and process VK_RETURN but delegate VK_TAB to the owner window.
• lParam
  Pointer to an MSG structure (or NULL if the system is performing a query).

Return Value

The return value is one or more of the following values, indicating which type of input the application processes.

DLGC_BUTTON Button. DLGC_DEFPUSHBUTTON Default push button. DLGC_HASSETSEL EM_SETSEL messages. DLGC_RADIOBUTTON Radio button. DLGC_STATIC Static control. DLGC_UNDEFPUSHBUTTON Non-default push button. DLGC_WANTALLKEYS All keyboard input. DLGC_WANTARROWS Direction keys. DLGC_WANTCHARS WM_CHAR messages. DLGC_WANTMESSAGE All keyboard input (the application passes this message in the MSG structure to the control). DLGC_WANTTAB TAB key.

Remarks

Although the DefWindowProc function always returns zero in response to the WM_GETDLGCODE message, the window procedure for the predefined control classes return a code appropriate for each class.

The WM_GETDLGCODE message and the returned values are useful only with user-defined dialog box controls or standard controls modified by subclassing.

Notification Requirements

• Minimum DLL Version None
• Header Declared in Winuser.h, include Windows.h
• Minimum operating systems Windows 95, Windows NT 3.1

Message Handler Macro

#define HANDLE_WM_GETDLGCODE(hwnd,wParam,lParam,fn) (LRESULT)(DWORD)(UINT)(fn)(hwnd,(LPMSG)(lParam))

This is sort of useless - you don't get the vitual key that windows is asking about!

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time