QLoggingCategory可以控制列印輸出類别和區域。友善在調試時，過濾掉不關心的列印資訊。
QLoggingCategory Class
The QLoggingCategory class represents a category, or 'area' in the logging infrastructure. More...
Header: #include <QLoggingCategory>
qmake: QT += core
Since: Qt 5.2
https://blog.csdn.net/u010168781/article/details/84667524![Objective-C-Category類别[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)