Saving the state of an activity before pressing the back button

Question

I am currently building an android app which requires saving the state of my variables and views when the back button is pressed. I know the onSaveInstanceState() would work for scenarios which involve change in orientation but how do I get it to save when I use the back button.

Answer 1

You may override finish() method and do saving there. This method is called when the activity is finished — that means, it's removed from activity stack. By default this happens when you press back button.

Answer 2

You can override,

@Override
public void onBackPressed() {
super.onBackPressed();
}

and save the state in Shared Preferences.

Answer 3

正如Sarge所说，您可以重写onFinish（）并将数据保存在首选项，AppDelegate等中。或者您可以保存数据并将其发送到上一个ActivityResult的活动中，或者可以尝试找到适当的活动标志，以便此操作活动不会被杀死。