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Marshal.PtrToStringAuto Method (IntPtr, Int32)

.NET Framework 1.1

Copies a specified number of characters from a string stored in unmanaged memory to a managed String.

[Visual Basic]
Overloads Public Shared Function PtrToStringAuto( _
   ByVal ptr As IntPtr, _
   ByVal len As Integer _
) As String
public static string PtrToStringAuto(
 IntPtr ptr,
 int len
public: static String* PtrToStringAuto(
 IntPtr ptr,
 int len
public static function PtrToStringAuto(
   ptr : IntPtr,
 len : int
) : String;


For Unicode platforms, the address of the first Unicode character.


For ANSI plaforms, the address of the first ANSI character.

The number of characters to copy.

Return Value

A managed string that holds a copy of the native string.


Exception Type Condition
ArgumentException len is less than zero.
ArgumentNullException ptr is a null reference (Nothing in Visual Basic).


On Unicode platforms, this method calls PtrToStringUni; on ANSI platforms, it calls PtrToStringAnsi. No transformations are done before these methods are called.

PtrToStringAuto 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. PtrToStringAnsi provides the opposite functionality of Marshal.StringToCoTaskMemAuto and Marshal.StringToHGlobalAuto.

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 | Marshal.PtrToStringAuto Overload List | StringToCoTaskMemAuto | StringToHGlobalAuto | PtrToStringUni | PtrToStringAnsi