Marshal::AllocHGlobal Method (IntPtr)

.NET Framework (current version)

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)

Syntax

public:
[SecurityCriticalAttribute]
static IntPtr AllocHGlobal(
	IntPtr cb
)

Parameters

cb: 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.

Exceptions

Exception	Condition
OutOfMemoryException	There is insufficient memory to satisfy the request.

Remarks

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.

Security

SecurityCriticalAttribute

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

Version Information

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