c++ - Working With SFML, getting "Unresolved External Symbol" Output

Question

So I'm making a pong clone, and I'm currently compiling it with the following output:

1>------ Build started: Project: Pong, Configuration: Debug Win32 ------ 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall sf::Image::Create(unsigned int,unsigned int,class sf::Color const &)"     (__imp_?Create@Image@sf@@QAEXIIABVColor@2@@Z) referenced in function "public: void   __thiscall Display::load_resources(void)" (?load_resources@Display@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Color::Color(unsigned char,unsigned char,unsigned char,unsigned char)" (__imp_??0Color@sf@@QAE@EEEE@Z) referenced in function "public: void __thiscall Display::load_resources(void)" (?load_resources@Display@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: bool __thiscall sf::Texture::LoadFromFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class sf::Rect<int> const &)" (__imp_?LoadFromFile@Texture@sf@@QAE_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABV?$Rect@H@2@@Z) referenced in function "public: void __thiscall Display::load_resources(void)" (?load_resources@Display@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: bool __thiscall sf::Font::LoadFromFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (__imp_?LoadFromFile@Font@sf@@QAE_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "public: void __thiscall Display::load_resources(void)" (?load_resources@Display@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall sf::Sprite::SetTexture(class sf::Texture const &,bool)" (__imp_?SetTexture@Sprite@sf@@QAEXABVTexture@2@_N@Z) referenced in function "public: void __thiscall Display::loadSprites(void)" (?loadSprites@Display@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall sf::Sprite::~Sprite(void)" (__imp_??1Sprite@sf@@UAE@XZ) referenced in function "public: void __thiscall Ball::setSprite(class sf::Sprite)" (?setSprite@Ball@@QAEXVSprite@sf@@@Z) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class sf::Sprite & __thiscall sf::Sprite::operator=(class sf::Sprite const &)" (__imp_??4Sprite@sf@@QAEAAV01@ABV01@@Z) referenced in function "public: void __thiscall Ball::setSprite(class sf::Sprite)" (?setSprite@Ball@@QAEXVSprite@sf@@@Z) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Sprite::Sprite(void)" (__imp_??0Sprite@sf@@QAE@XZ) referenced in function "public: __thiscall Ball::Ball(void)" (??0Ball@@QAE@XZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall sf::Transformable::SetPosition(float,float)" (__imp_?SetPosition@Transformable@sf@@QAEXMM@Z) referenced in function "public: void __thiscall Ball::updateSprite(void)" (?updateSprite@Ball@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Image::~Image(void)" (__imp_??1Image@sf@@QAE@XZ) referenced in function __unwindfunclet$??0Display@@QAE@XZ$0 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Texture::~Texture(void)" (__imp_??1Texture@sf@@QAE@XZ) referenced in function __unwindfunclet$??0Display@@QAE@XZ$0 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Font::~Font(void)" (__imp_??1Font@sf@@QAE@XZ) referenced in function __unwindfunclet$??0Display@@QAE@XZ$0 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Image::Image(void)" (__imp_??0Image@sf@@QAE@XZ) referenced in function "public: __thiscall Display::Display(void)" (??0Display@@QAE@XZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Texture::Texture(void)" (__imp_??0Texture@sf@@QAE@XZ) referenced in function "public: __thiscall Display::Display(void)" (??0Display@@QAE@XZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Font::Font(void)" (__imp_??0Font@sf@@QAE@XZ) referenced in function "public: __thiscall Display::Display(void)" (??0Display@@QAE@XZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Sprite::Sprite(class sf::Sprite const &)" (__imp_??0Sprite@sf@@QAE@ABV01@@Z) referenced in function "public: void __thiscall Game::reset(void)" (?reset@Game@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static bool __cdecl sf::Keyboard::IsKeyPressed(enum sf::Keyboard::Key)" (__imp_?IsKeyPressed@Keyboard@sf@@SA_NW4Key@12@@Z) referenced in function "public: void __thiscall Game::update(void)" (?update@Game@@QAEXXZ) 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall sf::Window::~Window(void)" (__imp_??1Window@sf@@UAE@XZ) referenced in function _main 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall sf::Window::Close(void)" (__imp_?Close@Window@sf@@QAEXXZ) referenced in function _main 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall sf::Window::Display(void)" (__imp_?Display@Window@sf@@QAEXXZ) referenced in function _main 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::Window::Window(class sf::VideoMode,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,unsigned int,struct sf::ContextSettings const &)" (__imp_??0Window@sf@@QAE@VVideoMode@1@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@IABUContextSettings@1@@Z) referenced in function _main 
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sf::VideoMode::VideoMode(unsigned int,unsigned int,unsigned int)" (__imp_??0VideoMode@sf@@QAE@III@Z) referenced in function _main 
1>C:UsersOwnerDocumentsVisual Studio 2010ProjectsPongDebugPong.exe : fatal error LNK1120: 22 unresolved externals 

All I've read says I'm linking incorrectly, but I have all the files I should need in the include section... What am I doing wrong?

Answer 1

If you are linking the static SFML libraries you need to define SFML_STATIC in the preprocessor section of your project configuration.

If you do not do this you will get __declspec(dllimport) related linking errors as the headers no longer match the libraries they were built with.