The LocalLock function locks a local memory object and returns a pointer to the first byte of the object’s memory block. The memory block associated with a locked memory object cannot be moved or discarded. For memory objects allocated with the LMEM_MOVEABLE flag, the function increments the object’s lock count.
LPVOID LocalLock(
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HLOCAL hMem |
// handle of local memory object |
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); |
If the function succeeds, the return value is a pointer to the first byte of the memory block.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
The internal data structures for each memory object include a lock count that is initially zero. For movable memory objects, LocalLock increments the count by one, and the LocalUnlock function decrements the count by one. For each call that a process makes to LocalLock for an object, it must eventually call LocalUnlock. Locked memory will not be moved or discarded unless the memory object is reallocated by using the LocalReAlloc function. The memory block of a locked memory object remains locked in memory until its lock count is decremented to zero, at which time it can be moved or discarded.
Memory objects allocated with the LMEM_FIXED flag always have a lock count of zero. For these objects, the value of the returned pointer is equal to the value of the specified handle.
If the specified memory block has been discarded or if the memory block has a zero-byte size, this function returns NULL.
Discarded objects always have a lock count of zero.