Recently encountered a problem, that is
Such a registry entry, in QT, can read the key on the left side of the registry, but cannot get the value on the right side,
Found someone who had the same problem before: http://www.qtcn.org/bbs/read-htm-tid-55782.html
其实，这个东西Qt的文档中说的很明确：
Note that the backslash character is, as mentioned, used by QSettings to separate subkeys. As a result, you cannot read or write windows registry entries that contain slashes or backslashes; you should use a native windows API if you need to do so.
In this case, you need to call the windows API in QT to solve it.
(1) Add the static libraries and header files required by the windows API to operate the registry in QT
In the project pro file add:
LIBS += -lAdvapi32
add header file
#include <qt_windows.h>
（2）
References:
When using Windows registration functions such as RegOpenKeyEx, the compilation cannot resolve the problem https://blog.csdn.net/linuxsmallping/article/details/51722648