'mainwindow' has not been declared意思 'mainwindow'hasnotbeendeclared意思 'mainwindow'hasnotbeendeclared是一个编程错误信息，它意味着在当前的代码作用域或上下文中，mainwindow这个标识符（可能是一个变量、类、函数名等）没有被声明或定义。这个错误通常出现在以下几种情况：1.拼写或大小写错误：你可能在其他...
1、头文件没加 2、调用函数者的头文件在XXX头文件的下方
1、头文件没加 2、调用函数者的头文件在XXX头文件的下方
你可以在文件头上定义 #define Q0bject 就可以编译通过了！首先确认 Q0bject 还是 QObject；
Qt error --- 'XXX' has not been declared,1、头文件没加2、调用函数者的头文件在XXX头文件的下方
你没有拉入"stdio.h" 或拉入头文件的顺序不正确。或你用的是unicode 版本。如果你用的是VS8以后的版本的话，选中memcpy,按下F12会出现memcpy所在的库文件这样你就知道拉入什么头文件了
/home/ros/RobCode/mobot/src/mobot/src/send_client.cpp:38:13: error: ‘rclcpp::executor’ has not been declared 38| rclcpp::executor::FutureReturnCode::SUCCESS) | ^~~~ make[2]: *** [CMakeFiles/send_client.dir/build.make:63:CMakeFiles/send_client.dir/src/send_client.cpp.o] 错误1...
是编译错误吗？大概是你没有声明math吧。这句话翻译就是math不曾被声明。
When launching an error appears: ERROR: 'Namespace for prefix 'xsi' has not been declared.'. I suppose that something with namespace declaration should be done. Is there any way to declare namepace URI in xpath query, or there is a better solution? java xml dom xpath namespaces Share ...
DateTime.h:40:12: error: ‘std::get_time’ has not been declared using std::get_time; The server's compiler has no problem finding mtkime in case that info is of help. My Mac compiler version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include...