Finish parent and current activity in Android

user_143378 0
Viewed 93379

I have 3 activities. Activity A which leads to activity B, which in turn can go back to activity A or start activity C. However, if I press back in activity C the app should close.

To sum up:

  • Activity A starts activity B
  • Pressing Back on activity B should lead to A
  • Activity B starts activity C
  • Pressing Back on activity C should close the app

How should I go from activity B to C? This code currently gives me a NullPointerException on the last line:

Intent intent=new Intent(ActivityB.this, ActivityC.class);
startActivity(intent);
ActivityB.this.finish();
ActivityB.this.getParent().finish();

If I switch the last two lines I also get a null pointer.

android-activity android
16 Answers

You can use finishAffinity() , it will close Current & all Parent Activities of the Current Activity.

Note : But any results from Child Activity to Parent Activity will not be handled.

Hope, it helps !!

user_51936080

You can just override the back key behavior:

Activity A starts activity B
Pressing Back on activity B should lead to A
Activity B starts activity C
Pressing Back on activity C should close the app

Note that I don't call super from onBackPressed. This also allows you to override the browse stack mechanism for Android, which I find to be a big advantage, since currently there doesn't seem to be a way to clear the single oldest item from the browse stack in a simple way.

public class B extends Activity
{
    ...
    @Override
    public void onBackPressed()
    {
        // Start activity A
        Intent aIntent = new Intent(this, A);
        startActivity(bIntent);
    }
    ...
}

public class C extends Activity
{
    ...
    @Override
    public void onBackPressed()
    {
        // Close
        finish();
    }
    ...
}

You can specifically finish the parent activity if needed too, but using this method, you don't have to worry about it.

user_1866360

Create instance of ActivityB.

on ActivityB.java

public static ActivityB instanceOfActivityB;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    instanceOfActivityB = this;
}

on ActivityC.java

void onClose() {
   ActivityB.instanceOfActivityB.finish();
   finish();
}

Hope it helps!

user_57015880
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