sdk/samples/all in on code/Visual Studio 2008/CppCLINativeDllWrapper/NativeMethods.cpp

   1 /****************************** Module Header ******************************\
   2 Module Name:  NativeMethods.cpp
   3 Project:      CppCLINativeDllWrapper
   4 Copyright (c) Microsoft Corporation.
   5
   6 The code in this file implements the C++/CLI wrapper classes that allow you
   7 to call from any .NET code to the functions exported by a native C++ DLL
   8 module.
   9
  10   CSCallNativeDllWrapper/VBCallNativeDllWrapper (any .NET clients)
  11           -->
  12       CppCLINativeDllWrapper (this C++/CLI wrapper)
  13               -->
  14           CppDynamicLinkLibrary (a native C++ DLL module)
  15
  16 The NativeMethods class wraps the global functions exported by
  17 CppDynamicLinkLibrary.dll.
  18
  19 The interoperability features supported by Visual C++/CLI offer a
  20 particular advantage over other .NET languages when it comes to
  21 interoperating with native modules. Apart from the traditional explicit
  22 P/Invoke, C++/CLI allows implicit P/Invoke, also known as C++ Interop, or
  23 It Just Work (IJW), which mixes managed code and native code almost
  24 invisibly. The feature provides better type safety, easier coding, greater
  25 performance, and is more forgiving if the native API is modified. You can
  26 use the technology to build .NET wrappers for native C++ classes and
  27 functions if their source code is available, and allow any .NET clients to
  28 access the native C++ classes and functions through the wrappers.
  29
  30 This source is subject to the Microsoft Public License.
  31 See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  32 All other rights reserved.
  33
  34 THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
  35 EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
  36 WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
  37 \***************************************************************************/
  38
  39 #pragma region Includes
  40 #include "NativeMethods.h"
  41 using namespace CppCLINativeDllWrapper;
  42
  43 #include <msclr/marshal.h>
  44 using namespace msclr::interop;
  45 #pragma endregion
  46
  47
  48 int NativeMethods::GetStringLength1(String ^ str)
  49 {
  50     // Marshal System::String to PCWSTR, and call the C++ function.
  51     marshal_context ^ context = gcnew marshal_context();
  52     PCWSTR pszString = context->marshal_as<const wchar_t*>(str);
  53     int length = ::GetStringLength1(pszString);
  54     delete context;
  55     return length;
  56 }
  57
  58 int NativeMethods::GetStringLength2(String ^ str)
  59 {
  60     // Marshal System::String to PCWSTR, and call the C++ function.
  61     marshal_context ^ context = gcnew marshal_context();
  62     PCWSTR pszString = context->marshal_as<const wchar_t*>(str);
  63     int length = ::GetStringLength2(pszString);
  64     delete context;
  65     return length;
  66 }
  67
  68 int NativeMethods::Max(int a, int b, CompareCallback ^ cmpFunc)
  69 {
  70     // Convert the delegate to a function pointer.
  71     IntPtr pCmpFunc = Marshal::GetFunctionPointerForDelegate(cmpFunc);
  72     return ::Max(a, b, static_cast<::PFN_COMPARE>(pCmpFunc.ToPointer()));
  73 }