Invokes the default processing for all messages passed to an object.
HRESULT OnDefWindowMessage(
UINT msg, //Message Identifier as provided by Windows
WPARAM wParam, //Message parameter as provided by Windows
LPARAM lParam, //Message parameter as provided by Windows
LRESULT* plResult //Pointer to message result code
);
A windowless object can explicitly invoke the default processing for a window message by calling this method. A container dispatches window messages to its windowless objects by calling IOleInPlaceObjectWindowless::OnWindowMessage. The object usually returns S_FALSE to indicate that it did not process the message. Then, the container can perform the default behavior for the message by calling the Windows API function DefWindowProc.
Instead, the object can call this method on the container's site object to explicitly invoke the default processing. Then, the object can take action on its own if the container does not handle the message.
The container must pass the following window messages to its default window procedure (the DefWindowProc Windows API function) and return S_OK. Note that *plResult should contain the value returned by DefWindowProc.
WM_MOUSEMOVE | WM_DEADCHAR |
WM_XBUTTONxxx | WM_SYSKEYUP |
WM_KEYDOWN | WM_SYSCHAR |
WM_KEYUP | WM_SYSDEADCHAR |
WM_CHAR | WM_IMExxx |
The container can either process the window messages as its own and return S_OK or not do anything and return S_FALSE.
WM_SETCURSOR | |
WM_CONTEXTMENU | |
WM_HELP |
If the container returns S_FALSE, the object can take action to process the window message on its own.
Windows NT: Use version 4.0 or later. New for OC96.
Windows: Use Windows 95 or later. New for OC96.
Windows CE: Unsupported.
Header: Declared in ocidl.h.
IOleInPlaceObjectWindowless::OnWindowMessage