SDL2 - 未定義的引用 - Ubuntu

Question

我剛開始使用SDL2（在Ubuntu 13.04 x64上），一切都很順利，直到我嘗試使用SDL_image。

我加了這段代碼，加載圖片：

SDL_Texture* LoadImage(std::string file) 
{ 
    SDL_Texture* tex = NULL; 
    tex = IMG_LoadTexture(ren, file.c_str()); 
    if (tex == NULL) 
     throw std::runtime_error("Failed to load image: " + file + IMG_GetError()); 
    return tex; 
} 

我-lSDL2和-lSDL2_image鏈接，和我得到這個未定義的引用：

g++ -o "SDL" ./src/main.o -lSDL2 -lSDL2_image 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_malloc" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_memcmp" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_strncasecmp" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_memset" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_free" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_memcpy" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_sscanf" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_isspace" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_realloc" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_strcmp" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_strncmp" 
/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/libSDL2_image.so: riferimento non definito a "SDL_snprintf" 
collect2: error: ld returned 1 exit status 

我在做什麼錯??

Answer 1

你下載並編譯/安裝了庫嗎？ 試試這個：

sudo apt-get install libsdl-dev 

之後，你可以編譯和對SDL鏈接：

gcc `pkg-config --libs --cflags sdl` <sourcefile.c> 

Answer 2

這有可能改變庫的順序會解決這個問題。

g++ -o "SDL" ./src/main.o -lSDL2_image -lSDL2 

編號：linker tells me it can't resolve symbols, but they're there?