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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
Assemblies:   System.Runtime.InteropServices (in System.Runtime.InteropServices.dll)
  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function PtrToStringAnsi ( _
	ptr As IntPtr, _
	len As Integer _
) As String

Parameters

ptr
Type: System.IntPtr

The address of the first character of the unmanaged string.

len
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 Nothing; otherwise, this method returns Nothing.

ExceptionCondition
ArgumentException

len is less than zero.

PtrToStringAnsi is useful for custom marshaling or when mixing managed and unmanaged code. Because 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 the Marshal.StringToCoTaskMemAnsi and Marshal.StringToHGlobalAnsi methods.

The following 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.
	Console::WriteLine(myManagedString);
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

  • SecurityCriticalAttribute 

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

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