What's onCreate(Bundle savedInstanceState)

android bundle oncreate
user1077015 picture user1077015 · May 30, 2012 · Viewed 137.3k times · Source

Can anyone help me to know about the Bundle savedInstanceState in onCreate(Bundle savedInstanceState) I am newbie in Android. I try to understand it from developer.android.com. But I am not able to understand. Can anyone simplify it?

Answer

Dhruv Gairola picture Dhruv Gairola · May 30, 2012

If you save the state of the application in a bundle (typically non-persistent, dynamic data in onSaveInstanceState), it can be passed back to onCreate if the activity needs to be recreated (e.g., orientation change) so that you don't lose this prior information. If no data was supplied, savedInstanceState is null.

... you should use the onPause() method to write any persistent data (such as user edits) to storage. In addition, the method onSaveInstanceState(Bundle) is called before placing the activity in such a background state, allowing you to save away any dynamic instance state in your activity into the given Bundle, to be later received in onCreate(Bundle) if the activity needs to be re-created. See the Process Lifecycle section for more information on how the lifecycle of a process is tied to the activities it is hosting. Note that it is important to save persistent data in onPause() instead of onSaveInstanceState(Bundle) because the latter is not part of the lifecycle callbacks, so will not be called in every situation as described in its documentation.

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