My colleague she forgot the knock code and ask me for help. I know her phone is LG G3 D855 with Android Lillipop 5.0. I rooted her phone and installed some Apps for her several months ago...She said she tried all possible combination but in vain. Fortunately her phone is rooted, I told her I will tried to crack the knock code as soon as possible.
Thanks to God..I installed SSH droid on her phone several months ago for test and of course it had connected my Wifi AP before. When I tured her phone on and found it's ip address on my AP. So I used putty to logon to her phone, and typed bash command to find where the knock code configuration file is. Fortunately I found the combination in the file: knockcode_pref.xml.
The combination is "11442233", and I knew the knock code area is as below. So I told her the correct combination of knock code. She could use her phone now...