C++リンカエラー

Question

私はゲームを複数のファイルに分割しようとしました。これらのエラーが表示されます。

1>item.obj : error LNK2005: "private: static class sf::Image ctile::itile" (?itile@ctile@@0VImage@sf@@A) already defined in character.obj 
1>item.obj : error LNK2005: "class cmap maps" (?maps@@3Vcmap@@A) already defined in character.obj 
1>item.obj : error LNK2005: "class cmainchar mainch" (?mainch@@3Vcmainchar@@A) already defined in character.obj 
1>item.obj : error LNK2005: "class citemmanager itemmanager" (?itemmanager@@3Vcitemmanager@@A) already defined in character.obj 
1>item.obj : error LNK2005: "private: static class sf::Image citem::iitem" (?iitem@citem@@0VImage@sf@@A) already defined in character.obj 
1>item.obj : error LNK2005: "private: static class sf::Image cspell::ispell" (?ispell@cspell@@0VImage@sf@@A) already defined in character.obj 
1>item.obj : error LNK2005: "class sf::RenderWindow App" (?App@@3VRenderWindow@sf@@A) already defined in character.obj 
1>item.obj : error LNK2005: "class sf::View View" (?View@@3V0sf@@A) already defined in character.obj 
1>main.obj : error LNK2005: "private: static class sf::Image ctile::itile" (?itile@ctile@@0VImage@sf@@A) already defined in character.obj 
1>main.obj : error LNK2005: "class cmap maps" (?maps@@3Vcmap@@A) already defined in character.obj 
1>main.obj : error LNK2005: "class cmainchar mainch" (?mainch@@3Vcmainchar@@A) already defined in character.obj 
1>main.obj : error LNK2005: "class citemmanager itemmanager" (?itemmanager@@3Vcitemmanager@@A) already defined in character.obj 
1>main.obj : error LNK2005: "private: static class sf::Image citem::iitem" (?iitem@citem@@0VImage@sf@@A) already defined in character.obj 
1>main.obj : error LNK2005: "private: static class sf::Image cspell::ispell" (?ispell@cspell@@0VImage@sf@@A) already defined in character.obj 
1>main.obj : error LNK2005: "class sf::RenderWindow App" (?App@@3VRenderWindow@sf@@A) already defined in character.obj 
1>main.obj : error LNK2005: "class sf::View View" (?View@@3V0sf@@A) already defined in character.obj 
1>map.obj : error LNK2005: "private: static class sf::Image ctile::itile" (?itile@ctile@@0VImage@sf@@A) already defined in character.obj 
1>map.obj : error LNK2005: "class cmap maps" (?maps@@3Vcmap@@A) already defined in character.obj 
1>map.obj : error LNK2005: "class cmainchar mainch" (?mainch@@3Vcmainchar@@A) already defined in character.obj 
1>map.obj : error LNK2005: "class citemmanager itemmanager" (?itemmanager@@3Vcitemmanager@@A) already defined in character.obj 
1>map.obj : error LNK2005: "private: static class sf::Image citem::iitem" (?iitem@citem@@0VImage@sf@@A) already defined in character.obj 
1>map.obj : error LNK2005: "private: static class sf::Image cspell::ispell" (?ispell@cspell@@0VImage@sf@@A) already defined in character.obj 
1>map.obj : error LNK2005: "class sf::RenderWindow App" (?App@@3VRenderWindow@sf@@A) already defined in character.obj 
1>map.obj : error LNK2005: "class sf::View View" (?View@@3V0sf@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "private: static class sf::Image ctile::itile" (?itile@ctile@@0VImage@sf@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "class cmap maps" (?maps@@3Vcmap@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "class cmainchar mainch" (?mainch@@3Vcmainchar@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "class citemmanager itemmanager" (?itemmanager@@3Vcitemmanager@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "private: static class sf::Image citem::iitem" (?iitem@citem@@0VImage@sf@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "private: static class sf::Image cspell::ispell" (?ispell@cspell@@0VImage@sf@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "class sf::RenderWindow App" (?App@@3VRenderWindow@sf@@A) already defined in character.obj 
1>spell.obj : error LNK2005: "class sf::View View" (?View@@3V0sf@@A) already defined in character.obj 

Answer 1

問題は、クラスメンバー関数の定義がヘッダーファイルに配置されていることです。したがって、同じ定義は別々の翻訳単位に行きます。

また、ヘッダーファイルにinclude guardsを使用してください。

Answer 2

おそらく、メソッド定義は.hファイルになります。 .cppファイルで

#ifndef SOMETHING_H_ 
#define SOMETHING_H_ 

class Something { 
public: 
    int foo(); 
}; 

#endif // SOMETHING_H_ 

とメソッドの定義：：

その結果、あなたは警備員を含めると.hファイルで宣言をしてください、あなたの

における単一の定義の多くのコピーを持っています

#include "Something.h" 

int Something::foo() { 
    return 5; 
}