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

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:\Users\Owner\Documents\Visual Studio 2010\Projects\Pong\Debug\Pong.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.