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问题描述

我写它使用互操作的服务来访问功能于一身的本地C ++ DLL C#应用程序。我已经使用这些工作大约10个不同的功能。

I am writing a C# application which uses Interop services to access functions in a native C++ DLL. I am already using about 10 different functions which are working.

现在我不知道如何处理传递一个回调作为参数,以便该DLL可以调用我的code。

Now I am not sure how to handle passing a callback as a parameter so that the DLL can call my code.

下面是DLL的函数原型:

Here is the function prototype of the DLL:

typedef void (WINAPI * lpfnFunc)(const char *arg1, const char *arg2)

和,让我通过上述类型的功能:

And the function that allows me to pass the above type:

int WINAPI SetFunc(lpfnFunc f)

下面是我的C#code的委托和函数定义:

Here is my C# code for the delegate and function definitions:

public delegate void Func(string arg1, string arg2);

public static void MyFunc(string arg1, string arg2)

下面是我的C#code为SetFunc互操作功能:

Here is my C# code for the SetFunc Interop function:

[DllImport("lib.dll", CharSet = CharSet.Ansi)]
public static extern int SetFunc(Func lpfn);

和终于在这里是code,其中我所说的SetFunc功能,通过它我的回调:

And finally here is the code where I call the SetFunc function and pass it my callback:

SetFunc(new Func(MyFunc));

不幸的是我的函数没有被调用时是应该的。在SetFunc函数的返回值返回错误code代表成功的,所以要么它不叫我的功能,或者它不工作,因为我的code是错误的。

Unfortunately my function is not being called when it should be. The return value of the SetFunc function is returning the error code for a Success, so either it's not calling my function or it's not working because my code is wrong.

推荐答案

这对我的作品:

Calc.h(Calc.dll,C ++):

Calc.h (Calc.dll, C++):

extern "C" __declspec(dllexport) double Calc(double x, double y, double __stdcall p(double, double));

Calc.cpp(Calc.dll,C ++):

Calc.cpp (Calc.dll, C++):

#include "calc.h"

__declspec(dllimport) double Calc(double x, double y, double __stdcall p(double, double))
{
    double s = p(x*x, y*y);
    return x * y + s;
}

的Program.cs(SAMPLE.EXE,C#):

Program.cs (Sample.exe, C#):

class Program
{
    delegate double MyCallback(double x, double y);
    [DllImport("Calc.dll", CallingConvention = CallingConvention.Cdecl)]
    static extern double Calc(double x, double y, [MarshalAs(UnmanagedType.FunctionPtr)]MyCallback func);

    static void Main(string[] args)
    {
        double z = Calc(1, 2, (x, y) => 45);
    }
}

这篇关于通过互操作性/​​ PInvoke的传递一个C#回调函数的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-20 02:56