1->2->3 activities, at third "back button" I want to go to the first one

I have a MainActivity, then I call SecondActivity (where I choose a file whose data is given to ThirdActivity.

If back button is pushed, I want t开发者_C百科he app to go back yo MainActivity and not SecondActivity.

How can I do that?

There are two ways to do it.

1. In SecondActivity, call finish() immediately after you start Activity 3.

2. Pass in the NO_HISTORY flag in the Intent for SecondActivity when starting it in MainActivity.

Just after you call startActivity with the Intent for activity 3, call finish in activity 2:

//in activity 2

    Intent intent = new Intent(...);
    startActivity(intent);
    finish();

You could also override onKeyPressed() (or whatever it's called) for the back button and startActivity().