P/Invoke 从 C# 到 C++ 的外部方法

Question

我编写了以下 C++ 共享库：

#include "iostream"

#if defined(_WIN32) || defined(_WIN64)
    #define Q_DECL_EXPORT __declspec(dllexport)
    #define Q_DECL_IMPORT __declspec(dllimport)
#else
    #define Q_DECL_EXPORT
    #define Q_DECL_IMPORT
#endif

#ifdef MATINCHESS_LIBRARY
#  define MATINCHESS_API Q_DECL_EXPORT
#else
#  define MATINCHESS_API Q_DECL_IMPORT
#endif

using namespace std;

string* memory;

extern "C"
{
    MATINCHESS_API void Initialize();
    MATINCHESS_API void Uninitialize();
    MATINCHESS_API void Put(string text);
    MATINCHESS_API string Get();

    void Initialize()
    {
        memory = new string;
    }

    void Uninitialize()
    {
        delete memory;
    }

    void Put(string text)
    {
        memory->assign(text);
    }

    string Get()
    {
        return *memory;
    }
}

这是我的 C# 控制台应用程序：

using System;
using System.Runtime.InteropServices;

namespace MatinChess
{
    class MainClass
    {
        const string MatinChessDLL = "libMatinChessDLL.so";

        [DllImport(MatinChessDLL)]
        public static extern void Initialize();
        [DllImport(MatinChessDLL)]
        public static extern void Uninitialize();

        [DllImport(MatinChessDLL)]
        public static extern void Put(string text);

        [DllImport(MatinChessDLL)]
        public static extern string Get();

        public static void Main (string[] args)
        {
            Console.WriteLine ("Initializing...");
            Initialize ();
            Console.WriteLine ("Initialized");

            Console.WriteLine ("Write: ");
            Put (Console.ReadLine ());
            Console.WriteLine ("Value is put.");

            Console.WriteLine ("You wrote \"" + Get () + "\"");
            Console.ReadKey ();

            Console.WriteLine ("Uninitializing...");
            Uninitialize ();
            Console.WriteLine ("Uninitialized");
        }
    }
}

它安全地初始化并放置来自 ReadLine 的字符串，但是当它想要调用 Get 方法时，它崩溃了，并产生了很长的堆栈跟踪。

请帮我找出问题。

Answer 1

您无法将 std::string 从 C++ 编组到 C#。您必须使用字符缓冲区。看到这个问题：Passing strings from C# to C++ dll and back -- minimal example

P/Invoke 从 C# 到 C++ 的外部方法

P/Invoke external method from C# to C++

c#

c++

pinvoke

extern