Question

我目前正在尝试使用C ++和SFML按照此页面的说明构建一个小游戏：http://www.gamefromscratch.com/page/Game-From-Scratch-CPP-Edition-The-Introduction.aspx。我一直遇到以下错误：

||=== Build: Debug in Pong (compiler: GNU GCC Compiler) ===|
G:\Ashwin\WIP\Pong\Game.cpp|34|warning: enumeration value 'Uninitialized' not handled in switch [-Wswitch]|
G:\Ashwin\WIP\Pong\Game.cpp|34|warning: enumeration value 'ShowingSplash' not handled in switch [-Wswitch]|
G:\Ashwin\WIP\Pong\Game.cpp|34|warning: enumeration value 'Paused' not handled in switch [-Wswitch]|
G:\Ashwin\WIP\Pong\Game.cpp|34|warning: enumeration value 'ShowingMenu' not handled in switch [-Wswitch]|
G:\Ashwin\WIP\Pong\Game.cpp|34|warning: enumeration value 'Exiting' not handled in switch [-Wswitch]|
obj\Debug\Game.o||In function `ZN4Game5startEv':|
G:\Ashwin\WIP\Pong\Game.cpp|6|undefined reference to `Game::gameState'|
G:\Ashwin\WIP\Pong\Game.cpp|9|undefined reference to `Game::mainWindow'|
G:\Ashwin\WIP\Pong\Game.cpp|10|undefined reference to `Game::gameState'|
G:\Ashwin\WIP\Pong\Game.cpp|17|undefined reference to `Game::mainWindow'|
obj\Debug\Game.o||In function `ZN4Game9isExitingEv':|
G:\Ashwin\WIP\Pong\Game.cpp|22|undefined reference to `Game::gameState'|
obj\Debug\Game.o||In function `ZN4Game8gameLoopEv':|
G:\Ashwin\WIP\Pong\Game.cpp|34|undefined reference to `Game::gameState'|
G:\Ashwin\WIP\Pong\Game.cpp|38|undefined reference to `Game::mainWindow'|
G:\Ashwin\WIP\Pong\Game.cpp|39|undefined reference to `Game::mainWindow'|
G:\Ashwin\WIP\Pong\Game.cpp|43|undefined reference to `Game::gameState'|
G:\Ashwin\WIP\Pong\Game.cpp|31|undefined reference to `Game::mainWindow'|
||error: ld returned 1 exit status|
||=== Build failed: 11 error(s), 5 warning(s) (0 minute(s), 1 second(s)) ===|

以下是所有源文件的列表：

Pong.cpp

#include <iostream>
#include "Game.h"

int main(int argc, char** argv)
{
    Game::start();
    return 0;
}

Game.cpp

#include <iostream>
#include "Game.h"

void Game::start(void)
{
        if(gameState != Uninitialized)
            return;

        mainWindow.create(sf::VideoMode(1024,768,32),"Pang!");
        gameState = Game::Playing;

        while(!isExiting())
        {
            gameLoop();
        }

        mainWindow.close();
}

bool Game::isExiting()
{
        if(gameState == Game::Exiting)
            return true;
        else
            return false;
}

void Game::gameLoop()
{
        sf::Event currentEvent;
        while(mainWindow.pollEvent(currentEvent))
        {   

          switch(gameState)
            {
                    case Game::Playing:
                    {
                        mainWindow.clear(sf::Color(255,0,0));
                        mainWindow.display();

                        if(currentEvent.type == sf::Event::Closed)
                        {
                                gameState = Game::Exiting;
                        }
                    break;
                    }
            }
        }
}

Game.h

#ifndef GAME_H_INCLUDED
#define GAME_H_INCLUDED

#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>

class Game
{
public:
        static void start();
private:
        static bool isExiting();
        static void gameLoop();
        enum GameState {Uninitialized,ShowingSplash,Paused,ShowingMenu,Playing,Exiting};
        static GameState gameState;
        static sf::RenderWindow mainWindow;
};
#endif // GAME_H_INCLUDED

我怎样才能纠正这些错误？

Answer 1

让我从这里的评论中回答这个问题。正如@DeiDei已经指出gameState和mainWindow缺失。

实际上它们在本教程的第2部分页面上提到，就在game.cpp部分的底部：

Game::GameState Game::_gameState = Uninitialized; 
sf::RenderWindow Game::_mainWindow;

我必须删除下划线才能使其正常工作。

Code :: Blocks中的未定义引用与SFML 2,4

1 个答案: