问题描述

我正在用 C# 编写一个 GUI 工具来解析和显示另一个用 C 编写的程序的数据输出.为了解析数据，我需要知道在许多 C 头文件中指定的数据结构.因此，我需要将这些 C 头文件合并到我的 C# 项目中.我的问题是:

I am writing a GUI tool in C# to parse and display the data output of another program written in C. In order to parse the data I need to know the data structures which are specified in a number of C header files. Thus I need to incorporate those C header files into my C# project. My questions are:

1) 经过一些研究，我得出结论，最好的方法是在我的解决方案中创建一个新的 C++/CLI 项目，将 C 头文件导入这个新项目，编写一些充当瘦包装器的 C++/CLI 类对于 C 头文件中定义的数据结构，然后从 C# 代码中引用 C++/CLI 包装类.这是最好的方法，还是有更好的方法?

1) After some research I came to conclude that the best way is to create a new C++/CLI project in my solution, import the C header files into this new project, write some C++/CLI classes that act as thin wrappers for the data structures defined in the C header files, then reference the C++/CLI wrapper classes from the C# code. Is this the best approach, or is there a better way?

2) 我遇到了参考问题.这是我的简化代码来说明问题:

2) I ran into a reference problem. Here's my simplified code to illustrate the problem:

C++/CLI 项目中的原始 C 头文件

Original C header in C++/CLI project

#define ABC  0x12345

C++/CLI 项目中的包装类

Wrapper class in C++/CLI project

#include "my_c_header.h"

namespace C_Wrappers {
    public ref class MyWrapper {
        public:
            property unsigned int C_ABC {
                unsigned int get() { return ABC; }
            }
    }
 }

C#项目中的用户类

using C_Wrappers;
using System;

namespace DataViewer {
    public partial class MainForm : Form {
        private  MyWrapper myWrapper = new MyWrapper();
        public MainForm() {
            Console.WriteLine(myWrapper.C_ABC.ToString());
        }
    }
 }

在 C# 项目中，我添加了对 C++/CLI 项目的引用(使用右键单击 > 添加引用).在构建期间，我在 C# 项目中遇到错误:找不到类型或命名空间 'C_Wrappers'(您是否缺少 using 指令或程序集引用?)."

In the C# project I added a reference to the C++/CLI project (using right click > Add Reference). During build I got an error in the C# project: "The type or namespace 'C_Wrappers' could not be found (are you missing a using directive or an assembly reference?)."

我以为我做了我应该做的一切.我应该怎么做才能修复这个错误?

I thought I did everything I was supposed to. What should I do to fix this error?

推荐答案

在我自己的解决方案中，我有 4 个项目:

In my own solution, I had 4 projects:

1. C++ 项目和测试代码
2. C++ DLL 项目，仅使用动态链接从第一个项目源中编译 DLL
3. 包装器项目，它只是一个使用 C++/CLI 的适配器，它包装了原始 C++
4. C# WPF 项目，这是我的图形界面.

#pragma once
#define DLLEXP   __declspec( dllexport )

DLLEXP void pop_back(std::string& str);

DLLEXP std::string testReturnString();

DLLEXP int getRandomNumber();

1. 向解决方案添加一个新项目(Visual C++ 中的类库)(在本例中称为Wrapper")
2. 使用附加的包含目录添加本机项目的路径
3. 将本机项目添加为新项目的参考(右键单击 > 参考... > 添加新链接)
4. 在Properties > Linker > Input中，将本机dll的名称放在延迟加载DLL(本例中为Computations.dll)字段中

1. Add a new project (class library in Visual C++) (called "Wrapper" in this example) to the solution
2. Add the path to the native project with the additional Include directories
3. Add the native project as a reference for the new project (right click > References... > Add New Link)
4. In Properties > Linker > Input, put the name of the native dll in the delayed loading of DLLs (Computations.dll in this example) field

C++/CLI 代码

我的包装器只是一个看起来像这样的类(减去我自己的代码).

The C++/CLI code

My wrapper is only a class which looks something like this (minus my own code).

包装器.h

#include "Token.h" // include your C++ header

#include <string>
#include <iostream>

namespace Wrapper {

    // noticed the ref?
    public ref class TokenAnalyzer
    {

    public:
        TokenAnalyzer(){
        };

        void Init();
            // use the C++/CLI type, like String^ (handles)
        System::String^ ProcessLine(int lineNbr, System::String^ line);
    };
}

CPP 中没有什么特别之处，只是您必须包含 #include "stdafx.h".

Nothing special inside the CPP except that you have to include #include "stdafx.h".

它还应该构建到一个 DLL 中，您将把它包含在 C# 调试目录中.

It should also builds into a DLL which you will include inside the C# debug dir.

只是我在 SO 某处找到的一个有用功能，但不记得您可能需要的位置.它将 C++/CLI 字符串句柄转换为 C++ 标准字符串.

Just a useful function I found somewhere on SO but don't remember where that you might need. It convert C++/CLI String handle into a C++ standard string.

std::string MarshalString (String ^ s) {
        using namespace Runtime::InteropServices;
        const char* chars = 
            (const char*)(Marshal::StringToHGlobalAnsi(s)).ToPointer();
        std::string os = chars;
        Marshal::FreeHGlobal(IntPtr((void*)chars));
        return os;
    }

C# 项目

向解决方案添加一个新项目(C# Windows Form 或 WPF 或任何你想要的！)并将其设置为启动项目(right-点击 > 设置为启动项目).

The C# project

Add to the solution a new project (C # Windows Form or WPF or whatever you want!) and set it as the startup project (right-click > set as startup project).

1. 添加 C++/CLI 项目作为新项目的参考
2. 以源代码形式添加指令using Wrapper;

像这样使用它:

/// Store the C++/CLI Wrapper object.</summary>
private Wrapper.TokenAnalyzer mTokenAnalyzer = new TokenAnalyzer();

2016/05/06 更新

阿什温 花时间制作了一个 示例项目 和一个 博文教程可能会有所帮助.

Ashwin took the time to make a sample project and a blog post tutorial which may help further.

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