This function changes the size or the attributes of a specified local memory object. The size can increase or decrease.

HLOCAL LocalReAlloc(
UINT uBytes, 
UINT fuFlags 


  • hMem
    [in] Handle to the local memory object to be reallocated. This handle is returned by either the LocalAlloc or LocalReAlloc function.

  • uBytes
    [in] New size, in bytes, of the memory block. If fuFlags specifies the LMEM_MODIFY flag, this parameter is ignored.

  • fuFlags
    [in] Flag that 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 ignored. Otherwise, this parameter controls the reallocation of the memory object.

    The LMEM_MODIFY flag can be combined with the flag listed in the following table.

    Value Description
    LMEM_MOVEABLE You cannot combine LMEM_MOVEABLE with LMEM_MODIFY to change a fixed memory object into a movable one. If you do, the function returns an error.

    If this parameter does not specify LMEM_MODIFY, this parameter can be any combination of the flags listed in the following table.

    Value Description
    LMEM_MOVEABLE Enables the memory allocation to move if it cannot be allocated in place.
    LMEM_ZEROINIT Causes the additional memory contents to be initialized to zero if the memory object is growing in size.

Return Values

A handle to the reallocated memory object indicates success. NULL indicates failure. To get extended error information, call GetLastError.


If LocalReAlloc fails, the original memory is not freed and the original handle and pointer are still valid.

If LocalReAlloc reallocates a movable object, the return value is a handle to the memory object.

If LocalReAlloc reallocates a fixed object, the value of the handle returned is the address of the first byte of the memory block. To access the memory, a process can simply cast the return value to a pointer.


Runs on Versions Defined in Include Link to
Windows CE OS 1.0 and later Winbase.h   Lmem.lib

Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

See Also

GetLastError, LocalAlloc, LocalFree

 Last updated on Tuesday, July 13, 2004

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