c++ - 访问静态变量时未解析的外部符号

Question

class CommandManager {

public:
    void sendText(std::string command);
    static bool CommandManager::started;

private:


    bool parseCommand(std::string commands);

    void changeSpeed(std::vector<std::string> vec);
    void help(std::vector<std::string> vec);
};

这是客户端代码:

CommandManager::started = true;

将这两个文件链接在一起我得到:

1>UAlbertaBotModule.obj : error LNK2001: unresolved external symbol "public: static bool CommandManager::started" (?started@CommandManager@@2_NA)

1>C:\Development\School\cmput350-uofabot\UAlbertaBot\vs2008\Release\UAlbertaBot.dll : fatal error LNK1120: 1 unresolved externals

我哪里错了？

Answer 1

你做错了。

class CommandManager {

public:
    void sendText(std::string command);
    static bool started; //NOT this -> bool CommandManager::started
    //...
};

然后将静态成员的定义放在.cpp文件中为:

#include "CommandManager.h" //or whatever it is

bool CommandManager::started = true; //you must do this in .cpp file

现在您可以在客户端代码中使用 CommandManager::started。