Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

onSavedInstanceState vs. SharedPreferences

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

I want all UI to be present and saved through navigation of an application instance; however on application termination everything needs to default.

My 8th activity collects all UI and places into an email . . .fyi

I have read alot about both onSavedInstanceState & SharedPreferences way of saving the data as activities go back and forth . . .

Which would be better for me?

like image 550
SLYtiger Avatar asked May 05 '11 16:05

SLYtiger


2 Answers

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
like image 103
Aleadam Avatar answered Oct 17 '22 13:10

Aleadam


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.
like image 40
Joseph Earl Avatar answered Oct 17 '22 13:10

Joseph Earl