This message is sent to an I/O procedure to request that the last logical action (MMIOM_DELETE, MMIOM_BEGININSERT, MMIOM_ENDINSERT, MMIOM_UNDO, or MMIOM_REDO) be undone.

pmmioinfo (PMMIOINFO)

A pointer to an MMIOINFO data structure.

usMsg (USHORT)

Set to MMIOM_UNDO.

lParam1 (LONG)

This parameter is not used.

lParam2 (LONG)

This parameter is not used.

rc (ULONG)

Return codes indicating success or failure:

MMIO_SUCCESS

The request to the IOProc was successful.
MMIO_ERROR
An error code is returned.

---

[Back] [Next]