FAILED: MyTestHttp : && /usr/bin/c++ -g CMakeFiles/MyTestHttp.dir/main.cpp.o -o MyTestHttp && : /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::Http()': /home/hy-20/project/MyTestHttp/main.cpp:20: undefined reference to `curl_global_init' /usr/bin/ld: /home/hy-20/project/MyTestHttp/main.cpp:21: undefined reference to `curl_easy_init' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::~Http()': /home/hy-20/project/MyTestHttp/main.cpp:25: undefined reference to `curl_easy_cleanup' /usr/bin/ld: /home/hy-20/project/MyTestHttp/main.cpp:26: undefined reference to `curl_global_cleanup' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::setUrl(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': /home/hy-20/project/MyTestHttp/main.cpp:29: undefined reference to `curl_easy_setopt' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::setPostFields(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': /home/hy-20/project/MyTestHttp/main.cpp:31: undefined reference to `curl_easy_setopt' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::setMethod(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': /home/hy-20/project/MyTestHttp/main.cpp:35: undefined reference to `curl_easy_setopt' /usr/bin/ld: /home/hy-20/project/MyTestHttp/main.cpp:36: undefined reference to `curl_easy_setopt' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::setHeaders(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': /home/hy-20/project/MyTestHttp/main.cpp:41: undefined reference to `curl_slist_append' /usr/bin/ld: /home/hy-20/project/MyTestHttp/main.cpp:42: undefined reference to `curl_easy_setopt' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::setWriteFunction(std::function<void (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)> const&)': /home/hy-20/project/MyTestHttp/main.cpp:46: undefined reference to `curl_easy_setopt' /usr/bin/ld: /home/hy-20/project/MyTestHttp/main.cpp:47: undefined reference to `curl_easy_setopt' /usr/bin/ld: CMakeFiles/MyTestHttp.dir/main.cpp.o: in function `Http::perform()': /home/hy-20/project/MyTestHttp/main.cpp:50: undefined reference to `curl_easy_perform' collect2: error: ld returned 1 exit status ninja: build stopped: subcommand failed.

这是一个链接错误，编译器找不到 curl 库的函数。你需要在链接时加上 curl 库。如果你使用的是 CMake，可以在 CMakeLists.txt 中添加以下代码：

find_package(CURL REQUIRED)
target_link_libraries(YourProjectName ${CURL_LIBRARIES})

其中，YourProjectName 是你的项目名称。