1.c++编写的函数前要加 extern "C" __declspec(dllexport) WINAPI
例如:extern "C" __declspec(dllexport) int WINAPI function(int a,int b);编译完后将Mydll.dll拷贝到c#的.exe的同一目录下
2.c#调用[DllImport("Mydll.dll")]
例如:
[DllImport("Mydll.dll"]
public extern static int function(int a, int b);