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Windows Programming

Notes UINT uBytes, // new size of block
UINT uFlags // how to reallocate object
);
5.5.1 Parameters

hMem

It determines the local memory object to be reallocated. This handle is returned by either the
LocalAlloc or LocalReAlloc function.

UBytes

It states the new size, in bytes, of the memory block. If this parameter is zero and the uFlags
parameter states the LMEM_MOVEABLE flag, the function returns a handle to a memory object
that is marked as discarded. If uFlagsspecifies the LMEM_MODIFY flag, this parameter is ignored.
uFlags

It specifies how to reallocate the local memory object. If the LMEM_MODIFY flag is specified,
this parameter modifies the attributes of the memory object, and the uBytes parameter is
unobserved. Or else, this parameter handles the reallocation of the memory object.
The LMEM_MODIFY flag can be united with either or both of the following flags:

Flag Meaning
LMEM_DISCARDABLE Assigns discardable memory if the LMEM_MODIFY flag is also specified.
This flag is overlooked, unless the object was previously allocated as
movable or the LMEM_MOVEABLE flag is also specified.
LMEM_MOVEABLE You cannot merge LMEM_MOVEABLE with LMEM_MODIFY to change
a fixed memory object into a movable one. The function returns an error if
an application attempts this.

If uFlags does not state LMEM_MODIFY, this parameter can be any mixture of the following
flags:

Flag Meaning
LMEM_MOVEABLE If uBytes is zero, discards a formerly movable and discardable memory
block. If the objects lock count is not zero or the block is not movable and
discardable, the function fails.
If uBytes is nonzero, enables the system to move the reallocated block to a
new location without modifying the movable or fixed attribute of the
memory object. If the object is fixed, the handle returned may be dissimilar
from the handle stated in the hMem parameter. If the object is movable, the
block can be moved without invalidating the handle, even if the object is
currently locked by a previous call to the LocalLockfunction. To obtain the
new address of the memory block, use LocalLock.
LMEM_NOCOMPACT Avoids memory from being compacted or discarded to satisfy the allocation
request.
LMEM_ZEROINIT Causes the supplementary memory contents to be initialized to zero if the
memory object is growing in size.

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