LNK 2001未解決C++ SFML

Question

我想使用SFML庫在C++中圍繞屏幕移動一個字符。 每次做一個項目我都會得到相同的LNK 2001錯誤。

請向我解釋我做錯了什麼，如何解決它。我仍然是初學者，所以如果你有任何關於修復錯誤或編寫代碼的建議，我很樂意。

Main.cpp的：

#include "Game.cpp" 
#include "Game.h" 

int main() 
{ 
    Game Game; 

    Game.GameRun(); 
} 

Game.h：

#pragma once 

#include <SFML\Window.hpp> 
#include "Character.h" 

class Game 
{ 
public: 
    void GameRun(); 
    void UpdateGame(Character player); 
    void Controls(int sourceX, int sourceY, Character player); 
}; 

Character.h：

#pragma once 

#include <SFML\Graphics.hpp> 
#include <SFML\System.hpp> 
#include <SFML\Window.hpp> 
#include "Game.h" 

class Character 
{ 
public: 
    enum Direction {Down, Left, Right, Up}; 

    int characterX; 
    int characterY; 

    sf::Texture txt_character; 
    sf::Sprite spr_character; 
}; 

Game.cpp：

#include "Game.h" 
#include "Character.h" 

#include <iostream> 

inline void Game::GameRun() 
{ 
    sf::RenderWindow window(sf::VideoMode(800, 600), "SFML test"); 

    Character player; 

    player.characterX = 1; 
    player.characterY = Character::Down; 

    player.txt_character.loadFromFile("character sprite sheet.png"); 
    player.spr_character.setTexture(player.txt_character); 

    while(window.isOpen()) 
    { 
     Game::UpdateGame(player); 
    } 
} 

inline void Game::UpdateGame(Character player) 
{ 
    sf::Event event; 
    sf::RenderWindow window(sf::VideoMode(800, 600), "SFML test"); 

    while (window.pollEvent(event)) 
    { 
     if (event.type == sf::Event::Closed) 
     window.close(); 
    } 
    Game::Controls(player.characterX, player.characterY, player); 

    player.spr_character.setTextureRect(sf::IntRect(player.characterX * 32, player.characterY * 32, 32, 32)); 

    window.draw(player.spr_character); 
    window.display(); 
    window.clear(); 
} 

inline void Game::Controls(int sourceX, int sourceY, Character player) 
{ 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) 
    { 
     sourceY = Character::Up; 
     sourceX++; 
     if (sourceX * 32 >= player.txt_character.getSize().x) 
      sourceX = 0; 
     player.spr_character.move(0, -2); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) 
    { 
     sourceY = Character::Down; 
     sourceX++; 
     if (sourceX * 32 >= player.txt_character.getSize().x) 
      sourceX = 0; 
     player.spr_character.move(0, 2); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) 
    { 
     sourceY = Character::Left; 
     sourceX++; 
     if (sourceX * 32 >= player.txt_character.getSize().x) 
      sourceX = 0; 
     player.spr_character.move(-2, 0); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) 
    { 
     sourceY = Character::Right; 
     sourceX++; 
     if (sourceX * 32 >= player.txt_character.getSize().x) 
      sourceX = 0; 
     player.spr_character.move(2, 0); 
    } 
} 

錯誤：

1> main.obj：錯誤LNK2001：解析外部符號？ 「市民：靜態INT字:: characterY」（characterY @字符@@ 2HA）

1> main.obj：錯誤LNK2001：解析外部符號？ 「公共：靜態INT字符:: characterX」（characterX @字符@@ 2HA）

1> C：\用戶\ SONY \ Documents \ Visual Studio 2010 \ Pr ojects \自上而下游戲\調試\下的Game.exe：致命錯誤LNK1120：2周無法解析的外部

感謝：d

編輯：FYI我有沒有類的代碼，它是可以正常使用，這只是一個大在main.cpp中

編輯的代碼塊：鏈接到文件夾的程序：https://www.dropbox.com/s/3yyjti8zwu019s7/Top%20Down%20Game%20With%20Classes.rar

Answer 1

編輯2014年3月8日：我想你的來源。刪除Main.cpp文件中的#include "Game.cpp"和Game.cpp文件中的inline關鍵字。

背後的邏輯無法正常工作，所以我將其固定爲最小值，以便在修正編譯（鏈接）錯誤後立即生效。你應該嘗試我的代碼，看看它是否有用。

一點解釋第一

通過傳遞值的選手對象（當你有void someMethod(Character player)如）發送對象的副本的方法。所以當你對玩家對象進行更改時，這些更改僅針對副本而不是實際玩家。我改變了你的代碼，所以它發送了一個指針（void someMethod(Character * player)。該方法接收到一個指向實際播放器對象的指針，並且對該對象所作的更改反映在實際播放器對象上。 （有些人可能會說這是過度殺毒或太危險）。

這可能是代替：

• 參考void someMethod(Character& player)
• 或返回值Character someMethod(Character player)
• 或兩個Character someMethod(const Character& player)
• 混合或一個成員變量（在頭文件中定義）

另一件事是你保持sf :: Texture值你的角色類。 sf :: Texture實際上是「沉重的」對象，所以它們不應該被值傳遞並且應該保持爲指針。你可以做的最好的事情（並且我沒有在你的代碼中完成）是從Character類中完全移除sf :: Texture，並且只保留已經擁有sf :: Texture的sf :: Sprite（in一個優化的方式，所以你不打擾它）。

下面的代碼

Main.cpp的

#include "Game.h" 

int main() 
{ 
    Game Game; 

    Game.GameRun(); 
} 

Game.h

#ifndef GAME_H_ 
#define GAME_H_ 

//#include <SFML/Window.hpp> /* you don't need this */ 
#include <SFML/Graphics/RenderWindow.hpp> 


// forward declaration, this prevents recursive/circular dependencies. 
// only works with pointer or referenced type. 
class Character; 

class Game 
{ 
public: 
    void GameRun(); 

    // I change the param to pointer to Character for logic reasons. 
    // You were doing changes on a Character COPY of the player, 
    // which was deleted when leaving the scope of the functions. 
    void UpdateGame(Character * player); 
    void Controls(Character * player); 
private: 
    // I added this here, so you can create the window in the 
    // GameRun and UpdateGame methods where needed. 
    sf::RenderWindow window; 
}; 

#endif 

Game.cpp

#include "Game.h" 
#include "Character.h" 

#include <SFML/Window/Event.hpp> /* you only need this */ 

#include <iostream> 

void Game::GameRun() 
{ 
    // I moved the window creation here because you were 
    // creating a new window each update which made the windows 
    // flickers each frame, making it impossible to close properly. 
    window.create(sf::VideoMode(800, 600), "SFML test"); 

    Character * player = new Character(); 

    player->characterX = 1; 
    player->characterY = Character::Down; 

    // if the file isn't available, this will prevent further problems. 
    if (player->txt_character.loadFromFile("character.png")) 
    { 
     player->spr_character.setTexture(player->txt_character); 
    } 

    while (window.isOpen()) 
    { 
     Game::UpdateGame(player); 
    } 
} 

void Game::UpdateGame(Character * player) 
{ 
    sf::Event event; 


    while (window.pollEvent(event)) 
    { 
     if (event.type == sf::Event::Closed){ 

      window.close(); 

     } 
    } 
    Controls(player); 

// player.spr_character.setTextureRect(
//   sf::IntRect(player.characterX * 32, player.characterY * 32, 32, 
//     32)); 

    window.clear(); 
    window.draw(player->spr_character); 
    window.display(); 

} 

// You were already sending the player so I removed the other 
// params and used the player instead. 
void Game::Controls(Character * player) 
{ 
    int sourceX = player->characterX; 

    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) 
    { 
     player->characterY = Character::Up; 
     sourceX++; 
     if (sourceX * 32 >= player->txt_character.getSize().x) 
      sourceX = 0; 
     player->spr_character.move(0, -2); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) 
    { 
     player->characterY = Character::Down; 
     sourceX++; 
     if (sourceX * 32 >= player->txt_character.getSize().x) 
      sourceX = 0; 
     player->spr_character.move(0, 2); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) 
    { 
     player->characterY = Character::Left; 
     sourceX++; 
     if (sourceX * 32 >= player->txt_character.getSize().x) 
      sourceX = 0; 
     player->spr_character.move(-2, 0); 
    } 
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) 
    { 
     player->characterY = Character::Right; 
     sourceX++; 
     if (sourceX * 32 >= player->txt_character.getSize().x) 
      sourceX = 0; 
     player->spr_character.move(2, 0); 
    } 
    player->characterX = sourceX; 
} 

Character.h

#ifndef CHARACTER_H_ 
#define CHARACTER_H_ 

//#include <SFML\Graphics.hpp> 
//#include <SFML\System.hpp> 
//#include <SFML\Window.hpp> 
//#include "Game.h" 
#include <SFML/Graphics/Sprite.hpp> /* Don't include more than you need */ 
#include <SFML/Graphics/Texture.hpp> 

class Character 
{ 
public: 
    enum Direction {Down, Left, Right, Up}; 

    int characterX; 
    int characterY; 

    sf::Texture txt_character; // Don't keep the texture value, it's really heavy. 
    sf::Sprite spr_character; 
}; 

#endif 

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