PtrToStringAuto Method (IntPtr, Int32)
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Marshal.PtrToStringAuto Method (IntPtr, Int32)


Allocates a managed String and copies the specified number of characters from a string stored in unmanaged memory into it.

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

public static string PtrToStringAuto(
	IntPtr ptr,
	int len


Type: System.IntPtr

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


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

Type: System.Int32

The number of characters to copy.

Return Value

Type: System.String

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

Exception Condition

len is less than zero.

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. Because this method creates a copy of the unmanaged string's contents, you must free the original string as appropriate. PtrToStringAuto provides the opposite functionality of Marshal.StringToCoTaskMemAuto and Marshal.StringToHGlobalAuto.


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

.NET Framework
Available since 1.1
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