onbackpressed() 时如何刷新片段中的列表视图

Question

I want to refresh listview fragmentA when back pressed

example:

I click onitem in listview in FragmentA to FragmentB

and when I click back (in Activity) in FragmentB ,I want to refresh listview FragmentA.

sorry My english is not good.

How to set onViewCreated OR onResume in FragmentA ???

and My activity

@Override
    public void onBackPressed() {
        super.onBackPressed();

MyFragmentA

 @Override
    public void setItems(ArrayList<NotificationListModel> items,String last_page) {
        Log.d("NotificationFragment", "setItems ");
        this.notificationListModels=items;
        this.last_page=last_page;

        for (NotificationListModel notificationListModel: notificationListModels){
            notificationListModelArrayList.add(notificationListModel);
        }
        getData();
        if (getActivity()!=null) {
            int currentPosition = getListView().getFirstVisiblePosition();
            adapNotificationList = new AdapNotificationList(getActivity(), notificationListModelArrayList);
            setListAdapter(adapNotificationList);
            adapNotificationList.notifyDataSetChanged();
            getListView().setSelection(currentShowList);
            getListView().setSelectionFromTop(currentPosition + 1, 0);
        }
    }

Answer 1

Override onResume in Fragment A and call adapter.notifyDataSetChanged() or the function which is handling data refresh of your listview.

@Override
public void onResume() {
    super.onResume();
    adapter.notifyDataSetChanged();
    //OR
    callDataRefreshFunction();

}

You do not need to handle onBackPressed in Activity.

Answer 2

First check fragmentB is visible or not if visible then

@Override
    public void onBackPressed() {
        if(fragmentb.isVisible())
         {
           //update listview of fragment a
           adapter.notifyDataSetChanged()
         }
        else
          super.onBackPressed();
    }

Answer 3

I guess you are loading data from server into the listview. If so and you want to refresh the listview on back press then just don't override the backpressed method. Just remove this code from fragment B.

@Override
    public void onBackPressed() {
        super.onBackPressed();
    }

Answer 4

In fragment you need to refresh after back pressed try add this:

 @Override public void setUserVisibleHint(boolean isVisibleToUser) { super.setUserVisibleHint(isVisibleToUser); if (isVisibleToUser) { if (FragmentCreated) { //FragmentCreated = True in procedure onCreateView FragmentTransaction ft = getFragmentManager().beginTransaction(); ft.detach(this).attach(this).commit(); //This reloads current fragment } }else{ // fragment is no longer visible } }