c/c++中如何实现动态库动态加载的完整工程示例代码

# CMake 最低版本号要求 cmake_minimum_required (VERSION 2.8) # 项目信息 project (dll_test) # if(WIN32) message(STATUS "windows compiling...") add_definitions(-D_PLATFORM_IS_WINDOWS_) set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT") set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MTd") set(WIN_OS true) else(WIN32) message(STATUS "linux compiling...") add_definitions( -D_PLATFORM_IS_LINUX_) add_definitions("-Wno-invalid-source-encoding") # add_definitions("-O2") set(UNIX_OS true) set(_DEBUG true) endif(WIN32) # set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin) # 指定源文件的目录,并将名称保存到变量 SET(source_h_lib ${PROJECT_SOURCE_DIR}/lib/metaObject.h ) SET(source_h_src ${PROJECT_SOURCE_DIR}/src/dlload.h ${PROJECT_SOURCE_DIR}/src/register.h ) SET(source_cpp_src ${PROJECT_SOURCE_DIR}/src/dlload.cpp ${PROJECT_SOURCE_DIR}/src/register.cpp ${PROJECT_SOURCE_DIR}/src/test.cpp ) #头文件目录 include_directories( ${PROJECT_SOURCE_DIR}/lib ${PROJECT_SOURCE_DIR}/src ) add_subdirectory(${PROJECT_SOURCE_DIR}/lib ./lib) if (${UNIX_OS}) add_definitions( "-W" "-fPIC" "-Wall" # "-Wall -g" "-Werror" "-Wshadow" "-Wformat" "-Wpointer-arith" "-D_REENTRANT" "-D_USE_FAST_MACRO" "-Wno-long-long" "-Wuninitialized" "-D_POSIX_PTHREAD_SEMANTICS" "-DACL_PREPARE_COMPILE" "-Wno-unused-parameter" "-fexceptions" ) set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0") link_directories( "${EXECUTABLE_OUTPUT_PATH}"/linux ) # 指定生成目标 add_executable(dll_test ${source_h_lib} ${source_h_src} ${source_cpp_src}) #link target_link_libraries(dll_test testlib -ldl) endif(${UNIX_OS}) if (${WIN_OS}) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4819") add_definitions( "-D_CRT_SECURE_NO_WARNINGS" "-D_WINSOCK_DEPRECATED_NO_WARNINGS" "-DNO_WARN_MBCS_MFC_DEPRECATION" "-DWIN32_LEAN_AND_MEAN" ) #link_directories() if (CMAKE_BUILD_TYPE STREQUAL "Debug") # 指定生成目标 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG ${PROJECT_SOURCE_DIR}/bin) # 指定生成目标 add_executable(dll_testd ${source_h_lib} ${source_h_src} ${source_cpp_src}) link_directories( "${EXECUTABLE_OUTPUT_PATH}"/Debug ) else(CMAKE_BUILD_TYPE) set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE ${PROJECT_SOURCE_DIR}/bin) # 指定生成目标 add_executable(dll_test ${source_h_lib} ${source_h_src} ${source_cpp_src}) link_directories( "${EXECUTABLE_OUTPUT_PATH}"/Release ) endif (CMAKE_BUILD_TYPE) endif(${WIN_OS})