how-to-load-unmanaged-resources-into-a-byte-array.md

description	Learn more about: How to: Load Unmanaged Resources into a Byte Array
title	How to: Load Unmanaged Resources into a Byte Array
ms.custom	get-started-article
ms.date	11/04/2016
helpviewer_keywords	native resources, loading into Byte array unmanaged resources, loading into Byte array native resources
ms.assetid	cdada6cd-6d42-437a-a90f-44a0b18d6a93

How to: Load Unmanaged Resources into a Byte Array

This topic discusses several ways to load unmanaged resources into a xref:System.Byte array.

Examples

If you know the size of your unmanaged resource, you can preallocate a CLR array and then load the resource into the array using a pointer to the array block of the CLR array.

// load_unmanaged_resources_into_Byte_array.cpp
// compile with: /clr
using namespace System;
void unmanaged_func( unsigned char * p ) {
   for ( int i = 0; i < 10; i++ )
      p[ i ] = i;
}

public ref class A {
public:
   void func() {
      array<Byte> ^b = gcnew array<Byte>(10);
      pin_ptr<Byte> p =  &b[ 0 ];
      Byte * np = p;
      unmanaged_func( np );   // pass pointer to the block of CLR array.
      for ( int i = 0; i < 10; i++ )
         Console::Write( b[ i ] );
      Console::WriteLine();
   }
};

int main() {
   A^ g = gcnew A;
   g->func();
}

0123456789

This sample shows how to copy data from an unmanaged memory block to a managed array.

// load_unmanaged_resources_into_Byte_array_2.cpp
// compile with: /clr
using namespace System;
using namespace System::Runtime::InteropServices;

#include <string.h>
int main() {
   char buf[] = "Native String";
   int len = strlen(buf);
   array<Byte> ^byteArray = gcnew array<Byte>(len + 2);

   // convert any native pointer to IntPtr by doing C-Style cast
   Marshal::Copy( (IntPtr)buf, byteArray, 0, len );
}

See also

Using C++ Interop (Implicit PInvoke)