Qual evento Android é chamado apenas uma vez até que a atividade seja destruída?

Question

Estou procurando uma única resposta (mas posso estar fazendo a pergunta errada)

Pergunta - Algum evento só é chamado uma vez no total até que uma atividade seja destruída?

Eu pergunto porque quando meu usuário gira o telefone para paisagem oncreate e onstart estão ambos invocados, causando um recarregamento de tipos.

Estou procurando um evento que eu pudesse colocar comportamento em que só seria executado 1x (até que a atividade seja morta)

Obrigado antecipadamente

Answer 1

If it is specific to the Activity just check your savedInstanceState parameter in the onCreate event. If it is null, run your code, if not, your code has already been run.

Example:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    if(savedInstanceState == null) {
        // Run your code
    }        
}

savedInstanceState will always be null when onCreate is run for the first time, and it will be populated thereafter.

Answer 2

You don't really specify what you're trying to do with it, so I can't guarantee this is appropriate for your use, but Application.onCreate is only called once.

Answer 3

If you want to eliminate the recreation of your activity on an orientationchange you can listen for configchanges in the manifest.

    <activity
            android:name=".MyActivity"
            android:configChanges="orientation" >
    </activity>

And then you can override onConfigurationChanged like so:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged( newConfig );

    LinearLayout main = (LinearLayout) findViewById( R.id.mainLayout );
    main.requestLayout();
}

to recreate the layout so that it matches the new orientation, without recreating the entire activity.

Answer 4

Check http://developer.android.com/guide/topics/resources/runtime-changes.html to handle configuration changes and to maintain your huge data between them...if all you need to maintain between the configuration change is just the settings,you can use the onSavedInstanceState() and onRestoreInstanceState() callbacks and the given bundles.