Question

我正在尝试将一个函数指针从C＃传递到C ++ / CLI并得到一个Windows编译器错误，指出该语言不支持ManagedTakeCallback函数（C＃） - 我定义了{{1在C ++ / CLI互操作中。我的代码看起来像

C＃应用程序：

ManagedTakeCallback

和

C ++ / CLI interop dll h和cpp文件：

namespace ManagedConsoleApplication

{

class Callback
    {
        public delegate double DelegateAdd(double value1, double value2);

        public static double CallbackAdd(double value1, double value2)
        {
            return value1 + value2;
        }

        public static DelegateAdd delegateCallback = new DelegateAdd(Callback.CallbackAdd); //declare as static to prevent GC

    }

    class Program
    {
       // [DllImport("InteropDLL.dll", CallingConvention = CallingConvention.StdCall)]
       // public static extern void ManagedCallback(IntPtr pCallback);
        static void Main(string[] args)
        {
            InteropDLL io = new InteropDLL(); 
            Console.WriteLine("The Add return = {0}", io.ManagedAdd(3, 2));
            Console.WriteLine("Pass CallBack to Unmanaged code");
            Callback cb = new Callback();
            IntPtr intptr_delegate = Marshal.GetFunctionPointerForDelegate(Callback.delegateCallback); //convert delegate to function pointer which can be used by unmanaged code
            Console.WriteLine("The callback return is {0}", io.ManagedTakeCallback(intptr_delegate)); 
            Console.WriteLine("Please hit Enter to exit");
            String value = Console.In.ReadLine();
            //Console.WriteLine("End of program ", value);
        }
    }
}

然后，C ++ / CLI互操作层调用C DLL。我可以调用//HEADER namespace Interop { typedef double (__stdcall *PCallback)(double value1, double value2); public ref class InteropDLL { public: double ManagedAdd(double value1, double value2); public: double ManagedTakeCallback(PCallback pCallback); }; } //CPP double Interop::InteropDLL::ManagedAdd(double value1, double value2) { return NativeAdd(value1, value2); } double Interop::InteropDLL::ManagedTakeCallback(PCallback pCallback) { return NativeTakeCallback(); }互操作函数;但是，如果添加ManagedAdd，则会出现Windows编译器错误。我怀疑C＃应用程序没有通过ManagedTakeCallback函数正确编组函数指针，或者C ++ / CLI端的签名不正确？我非常感谢任何见解。

Answer 1

以下是网站上的评论：

“但是C＃不支持C ++函数指针，所以我们不能在这里调用C ++函数指针.C＃只有Delegate对象，我们必须通过Marshal.GetDelegateForFunctionPointer将函数指针转换为Delegate。它在System中声明。 Runtime.InteropServices如下：


public static Delegate GetDelegateForFunctionPointer (
      IntPtr ptr,
      Type t)

获得完整答案的链接： http://www.codeproject.com/Articles/27298/Dynamic-Invoke-C-DLL-function-in-C

将C＃函数指针传递给C ++ / CLI interop dll

1 个答案: