我想从C ++非托管代码调用一个C＃委托。无参数委托工作正常，但是带参数的委托崩溃了我的程序 [英] I want to call a C# delegate from C++ unmanaged code. A parameterless delegate works fine , but a delegate with parameters crashed my program

问题描述

以下是来自未经过编译的dll的函数的代码。它接受一个函数指针作为参数，并简单地返回被调用函数返回的值。

The Following is code of a function from a unmanged dll. It takes in a function pointer as argument and simply returns value returned by the called function.

extern __declspec(dllexport) int  _stdcall callDelegate(int (*pt2Func)());
extern __declspec(dllexport) int  _stdcall callDelegate(int (*pt2Func)())
{
    int r = pt2Func();
    return r;
}

在托管C＃代码中，我使用委托调用上面的umanged函数。 p>

In managed C# code I call the umanged function above with a delegate.

  unsafe public delegate int mydelegate( );

    unsafe public int delFunc()
    {
             return 12;
    }

    mydelegate d = new mydelegate(delFunc);
    int re = callDelegate(d);
   [DllImport("cmxConnect.dll")]
    private unsafe static extern int callDelegate([MarshalAs(UnmanagedType.FunctionPtr)] mydelegate d);

这一切都很好！但如果我想我的函数指针/委托接受参数，它崩溃了程序。
所以如果我修改代码如下我的程序崩溃。

This all works great !! but if I want my function pointer/delegate to take arguments it crashed the program. So if I modify the code as follows my program crashes.

修改的非托管c ++ -

Modified unmanaged c++ -

extern __declspec(dllexport) int  _stdcall callDelegate(int (*pt2Func)(int));
extern __declspec(dllexport) int  _stdcall callDelegate(int (*pt2Func)(int))
{
    int r = pt2Func(7);
    return r;
}

修改的C＃代码 -

Modified C# code -

unsafe public delegate int mydelegate( int t);

        unsafe public int delFunc(int t)
        {
                 return 12;
        }

        mydelegate d = new mydelegate(delFunc);
        int re = callDelegate(d);

推荐答案

函数指针的调用约定是错误的。看起来像这样：

The calling convention for the function pointer is wrong. Make it look like this:

 int (__stdcall * pt2Func)(args...)

这篇关于我想从C ++非托管代码调用一个C＃委托。无参数委托工作正常，但是带参数的委托崩溃了我的程序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IT屋！