fragment does not refresh when back button is pressed

Question

how can i refresh the view of a fragment, when the back button is pressed?

I've tried this in the onResume method of the fragment but it doesn't work.

Ok, here is the code

the layout look like:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:background="@color/mainscreen_bg">

<fragment
    android:id="@+id/topbar"
    android:name="de.app.applib.TopbarFragment"
    android:layout_width="match_parent"
    android:layout_height="@dimen/topbar_height"
    android:layout_alignParentTop="true"
    tools:layout="@layout/fragment_topbar" />

 <fragment
    android:id="@+id/position_list"
    android:name="de.app.applib.CriteriaListFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_below="@id/topbar"
    android:tag="CriteriaList"
    tools:layout="@layout/fragment_criterialist" />

The TopbarFragment has the following layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/topbar_bg" >

<ImageView android:id="@+id/topbar_home"
    android:layout_height="match_parent"
    android:layout_width="wrap_content"
    android:layout_alignParentLeft="true"
    android:gravity="center_vertical"
    android:src="@drawable/ic_ab_back_holo_light"
    android:visibility="invisible"
    android:padding="0dp"
    android:contentDescription="@string/none"
    android:layout_margin="0dp"/>
<ImageView  android:id="@+id/topbar_logo"
    android:src="@drawable/actionbar_logo"
    android:layout_height="30dp"
    android:layout_width="120dp"
    android:layout_centerVertical="true"
    android:padding="0dp"
    android:layout_margin="0dp"
    android:contentDescription="@string/none"
    android:layout_toRightOf="@id/topbar_home"/>


<ToggleButton
    android:id="@+id/topbar_btn_push_abo"
    android:layout_width="40dp"
    android:layout_height="match_parent"
    android:layout_alignBottom="@+id/topbar_btn_info"
    android:layout_toLeftOf="@id/topbar_btn_info"
    android:background="@drawable/topbar_btn_push_bg"
    android:paddingTop="@dimen/padding_topbar_btn_push"
    android:textOff=""
    android:textOn=""
    android:textSize="12sp" />

In the onCreateView() of the Fragment i set the textOn and textOff values of the toggleButton.

This Fragment is included in all activities.

Now, i want to update the text of the toggleButton when the user pressed the back button. I set the new text in the onResume() Method of the Fragment. This Method is called but the old text appears in the activity and not the new updated text.

 @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    Log.d(TAG,"onCreateView called");
    View v = inflater.inflate(ResourceUtils.getCustomizableLayoutID(getActivity(), "fragment_topbar"), container, false);
    subscrButton = (ToggleButton) v.findViewById(R.id.topbar_btn_push_abo);
    setCountOfNewAdds();



    private void setCountOfNewAdds() {
    int countOfNewAds = ((App)getActivity().getApplication()).getCountOfNewAds();
    subscrButton.setTextOff(countOfNewAds>0?""+countOfNewAds:"");
    subscrButton.setTextOn(countOfNewAds>0?""+countOfNewAds:"");
    subscrButton.invalidate();
}

    @Override
public void onResume() {
    super.onResume();
    setCountOfNewAdds();
}

score 3 · Answer 1 · answered Nov 18 '13 at 15:50

3

If your fragment call replace(), not add() method to switch to another fragment (SecondFragment), your fragment will be called again the onCreateView() method when the back button in SecondFragment is pressed

answered Nov 18 '13 at 15:50

thanhnh

241
1
2
5

1

i dont call add or repalce to add the fragment i get the fragment in the activity with the getSupportFragmentManager().findFragmentById() Method – Alex Nov 22 '13 at 11:17

Jonathon Fry · Answer 2 · 2013-11-22T12:23:46.270

1

You can capture the users back click in the activity that the Fragment is hosted in.

Then, you can call a refresh method in the Fragment to handle refreshing your view.

In your activity:

@Override
public void onBackPressed() {
    Fragment yourFragment = getSupportFragmentManager().findFragmentById("ID");
    (TopbarFragment) yourFragment.setCountOfNewAdds();
}

edited Nov 22 '13 at 12:23

answered Nov 18 '13 at 13:53

Jonathon Fry

3,042
3
23
30

score 1 · Accepted Answer · answered Dec 04 '13 at 20:17

the Solution for the Problem was to use Framelayout in the layout to include the fragment e.g.

<FrameLayout
android:id="@+id/topbar"
android:name="de.app.applib.TopbarFragment"
android:layout_width="match_parent"
android:layout_height="@dimen/topbar_height"
android:layout_alignParentTop="true"
tools:layout="@layout/fragment_topbar" />

and then use the FragmentManager to insert the Fragment in the onStart() Method

@Override
protected void onStart() {
    super.onStart();

    TopbarFragment topbarFragment = (TopbarFragment) getSupportFragmentManager().findFragmentById(R.id.topbar);
    if(topbarFragment == null) {
        topbarFragment = new TopbarFragment();
        getSupportFragmentManager().beginTransaction().replace(R.id.topbar, topbarFragment).commit();
        getSupportFragmentManager().executePendingTransactions();
    }
}

then the update in the onResume() Method works

score 0 · Answer 4 · answered Jun 19 '20 at 16:41

In my case I was receiving user location using LocationManager. First I opened another fragment (fragment B) and then returned to current (fragment A) with Back button. Then passed view variable (view == getView()) to a method that started locationManager.requestSingleUpdate.

After receiving onLocationChanged event that view variable oddly changed to another value, while getView() was right. So, when I later accessed any control with view.textview.text = "aaa" it didn't set new value, and the fragment didn't refresh. Also getView() is not always not null, it can be null, if you get it from onCreateView, but not from onViewCreated.

fragment does not refresh when back button is pressed

4 Answers4