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Marshal.StringToHGlobalAnsi Method

Copies the contents of a managed String into unmanaged memory, converting into ANSI format as it copies.

[Visual Basic]
Public Shared Function StringToHGlobalAnsi( _
   ByVal s As String _
) As IntPtr
public static IntPtr StringToHGlobalAnsi(
 string s
public: static IntPtr StringToHGlobalAnsi(
 String* s
public static function StringToHGlobalAnsi(
   s : String
) : IntPtr;


A managed string to be copied.

Return Value

The address, in unmanaged memory, to where s was copied, or 0 if a null reference (Nothing in Visual Basic) string was supplied.


Exception Type Condition
OutOfMemoryException There is insufficient memory available.
ArgumentException s is a null reference (Nothing in Visual Basic).


StringToHGlobalAnsi is useful for custom marshaling or when mixing managed and unmanaged code. Since this method allocates the unmanaged memory required for a string, always free the memory by calling FreeHGlobal. StringToHGlobalAnsi provides the opposite functionality of Marshal.PtrToStringAnsi.

Note   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.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

Marshal Class | Marshal Members | System.Runtime.InteropServices Namespace | FreeCoTaskMem | PtrToStringAnsi