Code::Blocks w/ MinGW: 将 libpng 静态链接到 dll

Question

我正在尝试将 libpng16.lib 链接到我的 .dll 文件，但我无法让它工作。我已经将libpng16.lib 和zlib.lib 包含在项目依赖项中（按正确的顺序，首先是libpng），但仍然出现png_* 链接错误。

即使我在谷歌搜索的其他解决方案也不起作用。

编辑：

这是日志：

mingw32-g++.exe -Wall  -O2  -std=c++11 -Wall -g    -c C:\Users\Mark\Documents\CodeBlocks\TextureLoader\TextureLoader.cpp -o obj\Release\TextureLoader.o
C:\Users\Mark\Documents\CodeBlocks\TextureLoader\TextureLoader.cpp: In static member function 'static unsigned int TextureLoader::PNG_Texture_Load(const char*)':
C:\Users\Mark\Documents\CodeBlocks\TextureLoader\TextureLoader.cpp:105:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
mingw32-g++.exe -shared  -Wl,--out-implib=bin\Release\libTextureLoader.a -Wl,--dll -LC:\MinGW\include  obj\Release\TextureLoader.o   -o bin\Release\TextureLoader.dll -lOpenGL32 -lGLu32 -s  C:\Users\Mark\Documents\CodeBlocks\TextureLoader\libpng16.lib C:\Users\Mark\Documents\CodeBlocks\TextureLoader\libpng16.lib 
obj\Release\TextureLoader.o: In function `ZN13TextureLoader16PNG_Texture_LoadEPKc':
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:27: undefined reference to `png_sig_cmp'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:33: undefined reference to `png_create_read_struct'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:41: undefined reference to `png_create_info_struct'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:50: undefined reference to `png_create_info_struct'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:59: undefined reference to `png_set_longjmp_fn'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:66: undefined reference to `png_init_io'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:68: undefined reference to `png_set_sig_bytes'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:70: undefined reference to `png_read_info'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:77: undefined reference to `png_get_IHDR'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:79: undefined reference to `png_read_update_info'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:81: undefined reference to `png_get_rowbytes'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:109: undefined reference to `png_read_image'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:123: undefined reference to `png_destroy_read_struct'
C:/Users/Mark/Documents/CodeBlocks/TextureLoader/TextureLoader.cpp:100: undefined reference to `png_destroy_read_struct'

Answer 1

链接期间未定义的符号通常表明您尝试链接的导入库有问题，或者工具集正在寻找的内容与导入实际提供的符号之间存在分歧。

话虽如此，mingw自带的gnu ld链接器应该可以看懂msvc.lib导入库。作为替代方案，您可以尝试通过将 libpng16.dll 传递给链接器来直接链接它。

例如，尝试使用以下命令链接：

g++.exe -shared -Wl,--out-implib=bin\Release\libTextureLoader.a -LC:\MinGW\include obj\Release\TextureLoader.o -o bin\Release\TextureLoader.dll -lOpenGL32 - lGLu32 path\location\of\your\libpng16.dll

请注意，您原始链接命令中的-LC:\MinGW\include 可能不正确。直接包含运行时和各种其他导入的库路径通常位于 mingw 的 lib 目录中，而不是包含目录中。例如，mines 位于G:\Mingw32-4.6.3\i686-w64-mingw32\lib。