An application-defined function used with the WIMRegisterMessageCallback or WIMUnregisterMessageCallback functions.
DWORD CALLBACK WIMMessageCallback( DWORD dwMessageId, WPARAM wParam, LPARAM lParam, PVOID pvUserData );
Parameters
dwMessageId
[in] Specifies the sent message.
wParam
[in] Specifies additional message information. The contents of this parameter depend on the value of the dwMessageId parameter.
lParam
[in] Specifies additional message information. The contents of this parameter depend on the value of the dwMessageId parameter.
pvUserData
[in] A handle that specifies the user-defined value passed to the WIMRegisterMessageCallback function.
Return Value
To indicate success and to enable other subscribers to process the message return WIM_MSG_SUCCESS. To prevent other subscribers from receiving the message, return WIM_MSG_DONE. To cancel an image apply or image capture, return WIM_MSG_ABORT_IMAGE when handling the WIM_MSG_PROCESS message.
Remarks
Call the WIMUnregisterMessageCallback function with the result index when the WIMMessageCallback function is no longer required.
Do not use WIM_MSG_ABORT_IMAGE to cancel the process as a shortcut method of extracting a single file. Windows® 7 Imaging API is multi-threaded and aborting a process will cancel all background threads, which may include the single file you want to extract. If you want to extract a single file, use the WIMExtractImagePath function.