onSavedInstanceState vs. SharedPreferences

Question

I have 7 activites all with back and forth navigation buttons between the rest; activites consist of editTexts, Spinners, textViews, TimePickers, DatePickers, and checkboxes

Answer 1

It will depend on how you want to manage the data. Both options (and more) are feasible:

• If you want to fill once and keep the data even if the app gets killed, use SharedPreferences.
• If it's volatile data that will have to be reentered differently some other time (i.e., days later), then use onSavedInstanceState.
• If you want to keep multiple datasets on the same device, then use a SQLiteDatabase

Answer 2

SharedPreferences

• Use for things that should always be remembered, no matter if the phone is turned off (eg for settings chosen in the settings screen of your app

onSavedInstanceState

• Use this for remembering things about the current state of your activity such as the currently selected tab on the screen. This allows you to recreate the same state after a rotation or if the app was killed due to low memory.
• The things saved in onSaveInstanceState will be forgotten after reboot, and when starting a new instance of an activity they will not be passed, so they are only for remembering the state of the activity

onRetainNonConfigurationInstance

• Use this for storing objects which take a long time to load so that you don't have to load them again when the phone is rotated.