cpp文件中的类类型重定义

Question

我制作了一个 cpp 和 h 文件并在其中创建了类，但是我在重新定义时遇到了错误，例如

错误 2 error C2011: 'ConsoleCommandHandler' : 'class' type redefinition C:\\Users\\Łukasz\\Desktop\\IRCClient-master\\Magic.cpp 7

还有其他人

错误 4 错误 C2371：'commandHandler'：重新定义； 不同的基本类型 C:\\Users\\Łukasz\\Desktop\\IRCClient-master\\Magic.cpp 62

错误 9 错误 C2084：函数 'ThreadReturn inputThread(void *)' 已经有一个主体 C:\\Users\\Łukasz\\Desktop\\IRCClient-master\\Magic.cpp 100

错误 14 错误 C2027：使用未定义类型 'ConsoleCommandHandler' C:\\Users\\Łukasz\\Desktop\\IRCClient-master\\Magic.cpp 105

这是文件

魔术文件

#include "Magic.h"

void signalHandler(int signal);


class ConsoleCommandHandler
{
public:
    bool AddCommand(std::string name, int argCount, void(*handler)(std::string /*params*/, IRCClient* /*client*/))
    {
        CommandEntry entry;
        entry.argCount = argCount;
        entry.handler = handler;
        std::transform(name.begin(), name.end(), name.begin(), towlower);
        _commands.insert(std::pair<std::string, CommandEntry>(name, entry));
        return true;
    }

    void ParseCommand(std::string command, IRCClient* client)
    {
        if (_commands.empty())
        {
            std::cout << "No commands available." << std::endl;
            return;
        }

        if (command[0] == '/')
            command = command.substr(1); // Remove the slash

        std::string name = command.substr(0, command.find(" "));
        std::string args = command.substr(command.find(" ") + 1);
        int argCount = std::count(args.begin(), args.end(), ' ');

        std::transform(name.begin(), name.end(), name.begin(), towlower);

        std::map<std::string, CommandEntry>::const_iterator itr = _commands.find(name);
        if (itr == _commands.end())
        {
            std::cout << "Command not found." << std::endl;
            return;
        }

        if (++argCount < itr->second.argCount)
        {
            std::cout << "Insuficient arguments." << std::endl;
            return;
        }

        (*(itr->second.handler))(args, client);
    }

private:
    struct CommandEntry
    {
        int argCount;
        void(*handler)(std::string /*arguments*/, IRCClient* /*client*/);
    };

    std::map<std::string, CommandEntry> _commands;
};

ConsoleCommandHandler commandHandler;

void msgCommand(std::string arguments, IRCClient* client)
{
    std::string to = arguments.substr(0, arguments.find(" "));
    std::string text = arguments.substr(arguments.find(" ") + 1);

    std::cout << "To " + to + ": " + text << std::endl;
    client->SendIRC("PRIVMSG " + to + " :" + text);
};

void joinCommand(std::string channel, IRCClient* client)
{
    if (channel[0] != '#')
        channel = "#" + channel;

    client->SendIRC("JOIN " + channel);
}

void partCommand(std::string channel, IRCClient* client)
{
    if (channel[0] != '#')
        channel = "#" + channel;

    client->SendIRC("PART " + channel);
}

void ctcpCommand(std::string arguments, IRCClient* client)
{
    std::string to = arguments.substr(0, arguments.find(" "));
    std::string text = arguments.substr(arguments.find(" ") + 1);

    std::transform(text.begin(), text.end(), text.begin(), towupper);

    client->SendIRC("PRIVMSG " + to + " :\001" + text + "\001");
}

ThreadReturn inputThread(void* client)
{
    std::string command;

    commandHandler.AddCommand("msg", 2, &msgCommand);
    commandHandler.AddCommand("join", 1, &joinCommand);
    commandHandler.AddCommand("part", 1, &partCommand);
    commandHandler.AddCommand("ctcp", 2, &ctcpCommand);

    while (true)
    {
        getline(std::cin, command);
        if (command == "")
            continue;

        if (command[0] == '/')
            commandHandler.ParseCommand(command, (IRCClient*)client);
        else
            ((IRCClient*)client)->SendIRC(command);

        if (command == "quit")
            break;
    }

#ifdef _WIN32
    _endthread();
#else
    pthread_exit(NULL);
#endif
}

魔法.h

#ifndef Magic_h
#define Magic_h
#include <iostream>
#include <signal.h>
#include <cstdlib>
#include <map>
#include <algorithm>
#include "src\Thread.h"
#include "src\IRCClient.h"



volatile bool running;

void signalHandler(int signal)
{
    running = false;
}

class ConsoleCommandHandler
{
public:
    bool AddCommand(std::string name, int argCount, void(*handler)(std::string /*params*/, IRCClient* /*client*/));
    void ParseCommand(std::string command, IRCClient* client);
private:
    struct CommandEntry
    {
        int argCount;
        void(*handler)(std::string /*arguments*/, IRCClient* /*client*/);
    };

    std::map<std::string, CommandEntry> _commands;
};
ConsoleCommandHandler commandHandler;

void msgCommand(std::string arguments, IRCClient* client)
{
    std::string to = arguments.substr(0, arguments.find(" "));
    std::string text = arguments.substr(arguments.find(" ") + 1);

    std::cout << "To " + to + ": " + text << std::endl;
    client->SendIRC("PRIVMSG " + to + " :" + text);
};

void joinCommand(std::string channel, IRCClient* client)
{
    if (channel[0] != '#')
        channel = "#" + channel;

    client->SendIRC("JOIN " + channel);
}

void partCommand(std::string channel, IRCClient* client)
{
    if (channel[0] != '#')
        channel = "#" + channel;

    client->SendIRC("PART " + channel);
}

void ctcpCommand(std::string arguments, IRCClient* client)
{
    std::string to = arguments.substr(0, arguments.find(" "));
    std::string text = arguments.substr(arguments.find(" ") + 1);

    std::transform(text.begin(), text.end(), text.begin(), towupper);

    client->SendIRC("PRIVMSG " + to + " :\001" + text + "\001");
}

ThreadReturn inputThread(void* client)
{
    std::string command;

    commandHandler.AddCommand("msg", 2, &msgCommand);
    commandHandler.AddCommand("join", 1, &joinCommand);
    commandHandler.AddCommand("part", 1, &partCommand);
    commandHandler.AddCommand("ctcp", 2, &ctcpCommand);

    while (true)
    {
        getline(std::cin, command);
        if (command == "")
            continue;

        if (command[0] == '/')
            commandHandler.ParseCommand(command, (IRCClient*)client);
        else
            ((IRCClient*)client)->SendIRC(command);

        if (command == "quit")
            break;
    }

#ifdef _WIN32
    _endthread();
#else
    pthread_exit(NULL);
#endif
}
#endif

Answer 1

问题是您在 .cpp 和 .h 文件中都定义了类。 请记住，当您 #include 某些内容时，编译器只是将 #include 指令替换为文件的内容。 所以你的“Magic.cpp”文件看起来像这样：

//// from Magic.h
#ifndef Magic_h
#define Magic_h
#include <iostream>
#include <signal.h>
#include <cstdlib>
#include <map>
#include <algorithm>
#include "src\Thread.h"
#include "src\IRCClient.h"

volatile bool running;

void signalHandler(int signal)
{
    running = false;
}

class ConsoleCommandHandler
{
// ...
};
//// end of #include "Magic.h"

void signalHandler(int signal);

class ConsoleCommandHandler
{
// ...
};

在同一个源文件中有同一个类的两个定义。

如果你只是想实现成员函数，你可以这样做：

// Magic.h
class ConsoleCommandHandler
{
public:
    bool AddCommand(std::string name, int argCount, void(*handler)(std::string /*params*/, IRCClient* /*client*/));
    // ...
};

和

// Magic.cpp

#include "Magic.h"

bool ConsoleCommandHandler::AddCommand(std::string name, int argCount, void(*handler)(std::string /*params*/, IRCClient* /*client*/))
{
    // implementation
}

- - 编辑 - -

您的下一个问题是“volatile bool running”和“void signalHandler”。

//// Magic.h

volatile bool running;

void signalHandler(int signal)
{
    running = false;
}

这些应该进入 .cpp 文件，否则您将在包含 .h 文件的每个 .cpp 文件中定义它们。 再次记住：#include 有效地将自身替换为文件的内容。 想一想。 你和我都知道“signalHandler”定义在一个 .h 文件中，但编译器没有——它看到的是你在每个 cpp 文件中定义了 signalHandler。