Marshal.ReAllocHGlobal Method

Resizes a block of memory previously allocated with AllocHGlobal.

Namespace: System.Runtime.InteropServices
Assembly: mscorlib (in mscorlib.dll)

public static IntPtr ReAllocHGlobal (
	IntPtr pv,
	IntPtr cb
public static IntPtr ReAllocHGlobal (
	IntPtr pv, 
	IntPtr cb
public static function ReAllocHGlobal (
	pv : IntPtr, 
	cb : IntPtr
) : IntPtr



A pointer to memory allocated with AllocHGlobal.


The new size of the allocated block.

Return Value

An IntPtr to the reallocated memory. This memory must be released using Marshal.FreeHGlobal.

Exception typeCondition


There is insufficient memory to satisfy the request.

ReAllocHGlobal is one of two memory allocation API methods in the Marshal class. (Marshal.ReAllocCoTaskMem is the other.) This method exposes the GlobalRealloc Win32 API method from Kernel32.dll. The returned pointer can differ from the original. For additional information about GlobalAlloc, see the MSDN Library.


This method uses SecurityAction.LinkDemand to prevent it from being called from untrusted code; only the immediate caller is required to have SecurityPermissionAttribute.UnmanagedCode permission. If your code can be called from partially trusted code, do not pass user input to Marshal class methods without validation. For important limitations on using the LinkDemand member, see Demand vs. LinkDemand.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0