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Marshal.PtrToStringAnsi Method (IntPtr, Int32)

Allocates a managed String, copies a specified number of characters from an unmanaged ANSI string into it, and widens each ANSI character to Unicode.

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

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
public static string PtrToStringAnsi(
	IntPtr ptr,
	int len


Type: System.IntPtr

The address of the first character of the unmanaged string.

Type: System.Int32

The byte count of the input string to copy.

Return Value

Type: System.String
A managed String that holds a copy of the native ANSI string if the value of the ptr parameter is not null; otherwise, this method returns null.


len is less than zero.

PtrToStringAnsi is useful for custom marshaling or when mixing managed and unmanaged code. Since this method creates a copy of the unmanaged string's contents, you must free the original string as appropriate. This method provides the opposite functionality of Marshal.StringToCoTaskMemAnsi and Marshal.StringToHGlobalAnsi.


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.

The following code example uses the PtrToStringAnsi method to create a managed string from an unmanaged char array.

using namespace System;
using namespace System::Runtime::InteropServices;

void main()
	// Create an unmanaged c string. 
	const char * myString = "Hello managed world (from the unmanaged world)!";

	// Convert the c string to a managed String.
	String ^ myManagedString = Marshal::PtrToStringAnsi((IntPtr) (char *) myString);

	// Display the string to the console.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0