Does QXlsx support *.xls format excel ?

[QingJingYouYuan]

I have a Excel 97-2003 format (.xls) file need to be read and write.
My question is

1. Does QXlsx support 97-2003 format (.xls) file ?
2. Is there any different code process between (.xls) and (.xlsx) ?
   Thanks a lot!

[j2doll]

Dear @QingJingYouYuan

The xls format is not supported.
The xls format is a file in binary format. xlsx is a zip compressed file based on xml that is used as an iso standard.