Finishing current activity from a fragment

Question

I have a fragment in an activity that I am using as a navigation drawer. It contains buttons that when clicked start new activities (startActivity from a fragment simply calls startActivity on the current activity).

For the life of me I can't seem to figure out how I would finish the current activity after starting a new one.

I am looking to achieve something like this in the fragment:

@Override
public void onClick(View view) {
    // TODO Auto-generated method stub
    if (view == mButtonShows) {
        Intent intent = new Intent(view.getContext(), MyNewActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
        finish();
    } 
}

But it seems Fragment.class does not implement finish() (like it implements startActivity(...)).

I would like the activity backstack cleared when they launch the 2nd activity. (so pressing back from the new activity would technically drop them back to the launcher)

Solution 1

When working with fragments, instead of using this or refering to the context, always use getActivity(). You should call

Java

getActivity().finish();

Kotlin

activity.finish()

to finish your activity from fragment.

Solution 2

Well actually...

I wouldn't have the Fragment try to finish the Activity. That places too much authority on the Fragment in my opinion. Instead, I would use the guide here: http://developer.android.com/training/basics/fragments/communicating.html

Have the Fragment define an interface which the Activity must implement. Make a call up to the Activity, then let the Activity decide what to do with the information. If the activity wishes to finish itself, then it can.

Solution 3

As mentioned by Jon F Hancock, this is how a fragment can 'close' the activity by suggesting the activity to close. This makes the fragment portable as is the reason for them. If you use it in a different activity, you might not want to close the activity.

Code below is a snippet from an activity and fragment which has a save and cancel button.

PlayerActivity

public class PlayerActivity extends Activity 
    implements PlayerInfo.PlayerAddListener {

    public void onPlayerCancel() {
       // Decide if its suitable to close the activity, 
       //e.g. is an edit being done in one of the other fragments?
       finish();
    }
}

PlayerInfoFragment, which contains an interface which the calling activity needs to implement.

public class PlayerInfoFragment extends Fragment {
   private PlayerAddListener callback; // implemented in the Activity

   @Override
   public void onAttach(Activity activity) {
     super.onAttach(activity);
     callback= (PlayerAddListener) activity;
   }

   public interface PlayerAddListener {
       public void onPlayerSave(Player p); // not shown in impl above
       public void onPlayerCancel();
   }

   public void btnCancel(View v) {
      callback.onPlayerCancel(); // the activity's implementation
   }
}

Solution 4

You should use getActivity() method in order to finish the activity from the fragment.

getActivity().finish();

Solution 5

In Fragment use getActivity.finishAffinity()

getActivity().finishAffinity();

It will remove all the fragment which pushed by the current activity from the Stack with the Activity too...

View more solutions

Comments

[coder_For_Life22]

When working with fragments instead of using this or refering to the context, always us getActivity(); when working with fragments

[Matjaz Kristl]

getActivity() can be null in some cases. What should we do then?

[Cristian]

@user983956 In such cases the activity is already destroyed, so just don't call finish.

[Daniel Bejan]

As a tip : getActivity can be null if you try to use it before inflating the view

[Sasquatch]

That's a good point, since a single activity can have multiple fragments present. As you mention, the preferred way for a fragment to communicate back to its activity is via an interface.

[Ahmed]

The Activity should be the controller/incharge not the fragment, you should rather callback the Activity though a callback interface and let the Activity decide if it should finish itself.

[user1923551]

Though solutions works correctly, design wise its wrong. fragment should not decide any thing directly, related to parent activity. You should call interaction listener method, intimating that you wanted him(parent activity) to close. Then parent activity will save any data(if there) and closes by using finish().

[omersem]

Also, if you have singletons injected in the activity, do not forget to destroy them, it will create memory leaks, or if there are callbacks remove them ie. , if (getActivity() != null) { getActivity().removeCallbacks(); getActivity().destroy(); }

[Filipe Brito]

Tell me the diference between your answer and the first answer above (by @coder_For_Life22)...

[Demotivated]

dont its a trap

[Zakaria M. Jawas]

finishAffinity() will remove all the activities that have the same affinity, so activities below the current activity which contains the fragment in the stack could be finished as well.

[Jamaldin Sabirjanov]

Use activity?.finish()

[Abhishek Dutt]

This has already been answered. While answering old questions, only do post them if they provide a new solution, is novel and unique.

[Chris]

This was already posted in June, 2020