Differences between two ways of QT creating folders

QDir There are two ways to create folders ：
mkdir() If there are subfolders in the folder to be created , Then this kind of creation is unsuccessful , Unless the parent folder of the subfolder already exists ！
mkpath() If there are subfolders in the created folder , No matter what, it will be created from the parent folder to the bottom subfolder , All will succeed ！

123/456
If 123 Already exist , Then both will succeed
If 123 non-existent , So use mkdir Failure

QFileInfo in absolutefilepath() and absolutepath() What's the difference? ？
absolutefilepath() Include the name of the current file
and absolutepath() Is the path where the current file is located , That is, the current path name is not included , Just to the upper floor
qdir Medium entryinfolist() How to filter functions . and .. file
dir. entryinfolist(QDir::Dirs|QDir::NoDotAndDotDot) In this way, these two files can be filtered out

How to transfer the read file into a string ？
QTextStream stream(&file);
QString str=stream. readall();