CODEWITHSUNDEEP
androidandroid-fragmentsfragment
Monster Hunter
Monster Hunter

Reputation: 866

DialogFragment dismiss() does not pop backstack

I have a simple DialogFragment that calls dismiss when exits, according to the documentation:

public void dismiss()

Dismiss the fragment and its dialog. If the fragment was added to the back stack, all back stack state up to and including this entry will be popped. Otherwise, a new transaction will be committed to remove the fragment.

however, I found that the fragment is still on the backstack after calling dismiss() so I have to click back button to clear it. Does anyone know why ?

here's my code:

public void onCreate(Bundle b) {
        super.onCreate(b);
        setContentView(R.layout.test_layout);

        class MyDialogFragment extends DialogFragment implements OnClickListener{

            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

                View v = inflater.inflate(R.layout.hello_world, container, false);

                Button b = (Button)v.findViewById(R.id.btn);
                b.setOnClickListener(this);

                return v;
            }

            @Override
            public void onClick(View v) {
                dismiss();
            }
        }

        getFragmentManager().beginTransaction().add(android.R.id.content, new MyDialogFragment(), "test").addToBackStack("b").commit();
    }

    @Override
    public void onBackPressed() {
        if (getFragmentManager().getBackStackEntryCount() > 0 ){
            getFragmentManager().popBackStack();
        } else {
            super.onBackPressed();
        }
    }
}

I also found out that if I don't override onBackPressed(), the back button simple doesn't work, no matter how many fragments I add to the activity, the back button always exits the activity right away.

Upvotes: 12

Views: 9280

Answers (3)

Priyanka
Priyanka

Reputation: 247

dismiss()
findNavController().navigate(FirstBottomSheetDialogDirections.actionFirstSheetToSecondSheet())

This code is always the wrong thing to do: dismiss() is an asynchronous operation that doesn't actually dismiss anything immediately. That is unlike the navigate() which does immediately update the NavController's state, stacking the new dialog destination on top of the previous one.

This means that when the asynchronous dismiss actually happens, it correctly removes the dialog and, because it is a navigation stack, removes everything on top of it - including your second dialog. However, due to a bug in the DialogFragmentNavigator, we don't actually dismiss that second dialog, which is why it appears to work, despite everything actually already being internally out of sync (thus causing the later crash).

The correct way to pop a destination and navigate to a new destination as an atomic, immediate operation is to use popUpTo and popUpToInclusive. Therefore you can fix the sample app by removing the call to dismiss() and updating the action to pop the first dialog as part of the navigate call:

<action
    android:id="@+id/action_firstSheet_to_secondSheet"
    app:destination="@id/secondSheet"
    app:popUpTo="@id/firstSheet"
    app:popUpToInclusive="true"/>

This correctly pops the first dialog off the back stack and then navigates to the new dialog destination.

please refer this link : https://issuetracker.google.com/issues/191073055

Upvotes: 0

pablopatarca
pablopatarca

Reputation: 634

That it's a wrong way to create a DialogFragment.

Never ever use the FragmentManager to show a DialogFragment. To be shown there are a method called show(FragmentTransacion, String).

In java:

MyDialogFragment mDialogFragment = new MyDialogFragment();
mDialogFragment.show(getFragmentManager(), "MyDialogFragment");

For another hand, to dismiss the dialog just do this:

mDialogFragment.dismiss()

Another think that I would like to highlight is that the MyDialogFragment class is defined inner onCreate method :'( Please, define the class outside the method or in another file if you want :)

Good Look!

Upvotes: 4

Delblanco
Delblanco

Reputation: 681

I can confirm what @Luksprog said in his comment: the dialog must be started through show(FragmentTransaction, String).

Note after looking the source: make sure to call addToBackStack(String) on the supplied transaction or else it still won't work.

Upvotes: 8

Related Questions