相关资料：
https://blog.csdn.net/technologyleader/article/details/82225205
http://blog.sina.com.cn/s/blog_a6fb6cc90101guc5.html
qDebug：调试信息
qWarning：警告信息
qCritical：严重错误
qFatal：致命错误
PS:release版本下会出现没有文件与行信息，需要在.pro中引入
DEFINES += QT_MESSAGELOGCONTEXT
PS:中文乱码问题处理：
输入时如下：
QString str = QStringLiteral("中文");
qDebug(str.toStdString().data());
写入文件时如下：
QFile file("d:/log.txt");
file.open(QIODevice::WriteOnly | QIODevice::Append);
QTextStream text_stream(&file);
text_stream.setCodec("utf-8");
text_stream << message << "\r\n";
file.flush();
file.close();
.pro
1 QT += core gui 2 3 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets 4 5 CONFIG += c++11 6 7 # The following define makes your compiler emit warnings if you use 8 # any Qt feature that has been marked deprecated (the exact warnings 9 # depend on your compiler). Please consult the documentation of the 10 # deprecated API in order to know how to port your code away from it. 11 DEFINES += QT_DEPRECATED_WARNINGS 12 13 # You can also make your code fail to compile if it uses deprecated APIs. 14 # In order to do so, uncomment the following line. 15 # You can also select to disable deprecated APIs only up to a certain version of Qt. 16 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0 17 18 SOURCES += \ 19 main.cpp \ 20 mainwindow.cpp 21 22 HEADERS += \ 23 mainwindow.h 24 25 FORMS += \ 26 mainwindow.ui 27 28 # Default rules for deployment. 29 qnx: target.path = /tmp/$${TARGET}/bin 30 else: unix:!android: target.path = /opt/$${TARGET}/bin 31 !isEmpty(target.path): INSTALLS += target