Resetting your android phone to factory mode so you can unlock your pattern lock will wipe out all your files so here's a way you can use to unlock the pattern lock and save your data.
1. First of all connect your device to the PC and make sure USB debugging is enabled.
2. Now on your Windows PC, Go to START>RUN>Type CMD.
3. Now one by one type the following commands in the command window:
“Adb shell cd/data/data/com.android.providers.settings/database sqlite3 settings.db update system set value=0 where name=’lock_pattern utolock update system set value=0 where
Name='lockscreen.lockedout permanently';.quit"
4. After applying the above stated command, reboot your device. Now after normal reboot, you will notice lock pattern screen, but this time you will have to choose to create a new pattern code.