ISimpleFrameSite::PreMessageFilter

Provides a site with the opportunity to process a message that is received by a control's own window before the control itself does any processing.

HRESULT PreMessageFilter(
  HWND hWnd,          //Handle of window receiving message
  UINT msg,           //Received message
  WPARAM wp,          //WPARAM of message
  LPARAM lp,          //LPARAM of message
  LRESULT* plResult,  //Pointer to variable to receive result of 
                      //message processing
  DWORD* pdwCookie    //Pointer to a variable used later
);

Parameters

hWnd: [in] Handle of the control window receiving the message.
msg: [in] Message received by the simple frame site.
wp: [in] The WPARAM of the message.
lp: [in] The LPARAM of the message.
plResult: [out] Pointer to the result variable to receive the result of the message processing.
pdwCookie: [out] Pointer to the DWORD variable that will be passed to PostMessageFilter if it is called later. This parameter should only contain allocated data if this method returns S_OK so it will also receive a call to PostMessageFilter which can free the allocation. The caller is not in any way responsible for anything returned in this parameter.

Return Values

S_OK: The simple frame site will not use the message in this filter so more processing can take place.
S_FALSE: The site has processed the message and no further processing should occur.
E_NOTIMPL: The site does not do any message filtering, indicating that PostMessageFilter need not be called later.
E_POINTER: The addresses in plResultor pdwCookie are not valid.

Remarks

Successful return values indicate whether the site wishes to allow further processing. S_OK indicates further processing, whereas S_FALSE means do not process further. S_OK also indicates that the control must later call ISimpleFrameSite::PostMessageFilter.

QuickInfo

  Windows NT: Use version 4.0 or later.
  Windows: Use Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in ocidl.h.