Marshal.AllocHGlobal Method (IntPtr)


Allocates memory from the unmanaged memory of the process by using the pointer to the specified number of bytes.

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

static member AllocHGlobal : 
        cb:nativeint -> nativeint


Type: System.IntPtr

The required number of bytes in memory.

Return Value

Type: System.IntPtr

A pointer to the newly allocated memory. This memory must be released using the Marshal.FreeHGlobal method.

Exception Condition

There is insufficient memory to satisfy the request.

AllocHGlobal is one of two memory allocation methods in the Marshal class. (Marshal.AllocCoTaskMem is the other.) This method exposes the Win32 LocalAlloc function from Kernel32.dll.

When AllocHGlobal calls LocalAlloc, it passes a LMEM_FIXED flag, which causes the allocated memory to be locked in place. Also, the allocated memory is not zero-filled.

For example code, see Marshal and AllocHGlobal.


requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1
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