The android activity lifecycle

THE ANDROID ACTIVITY LIFECYCLE

Active and Visible Lifetimes

The onPause

The onResume

ACTIVITY TERMINATION

Starting from HoneyComb onwards, you can prepare for app termination in the onStop.

If you are targeting pre-honeycomb, prepare for it as early as onPause

How to prepare for Termination

Close any connections or sockets

Maintaining State

onSaveInstanceState called immediately before onPause

onRestoreInstanceState is called immediately after onCreate but only if the app is being restarted after being terminated by the system

You can use these to restore your app the same state the user saw before their exited the app

Storing Data in Android

Saves battery not to keep fetching data

Two Types:

1.SharedPreferences - using persistent key-value pairs for primitive data types

2.Databases - Helps organise and find data easily

Contract

WEATHER AND LOCATION TABLES

SQLite OPneHelper

onUpgrade

Called when the database version has changed

Make sure to always change the version when you DB changes

If you modify the columns and add new ones, you might want to use the ALTER TABLE command to add missing columns to the new DB

Read/Writting to the DB

Writing.

1.Get a reference to the Writable database

2.Create a ContentValues object of what you want to insert

3.Insert the content values and get back the row ID

Reading4. All DB queries return cursor by default. A cursor is control structure that enables us

to traverse over the rows and columns of our result set