I added hex conversion to the output in the version at Crc校验码程序。crc校验码程序。crc校验码程序 - #2 by ABG
(draggable)
and got a result matching what you checked.
In the case of where you fed the program a byte sequence including 256 as a byte value, be aware that unsigned byte values should run from 0 to 255, so 256 is wrong.
Should the app complain about that, or silently "clean" it up?