从项目文件中删除"@"字符:

Remove the ''@'' characters from your project file:

CONFIG += c++11

使用GCC时，请检查编译输出窗口是否将C ++ 11选项传递给了编译器(-std = c ++ 11).使用Visual C ++时(根据错误代码可能是这种情况)，它必须是VS 2012或更高版本，因为旧版本不支持final.

When using GCC, check the compilation output window if the C++11 option is passed to the compiler (-std=c++11). When using Visual C++ (which seems to be case according the error code), it must be VS 2012 or later because older versions did not support final.