从另一个活动返回时，片段变为空白

Question

There are two activities in my app:

MainActivity (containing 3 fragments)

• FragmentHome
• FragmentOrders
• FragmentAccount

AccountEditActivity

The code to set fragments in MainActivity is this:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
    navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);

    // set Home as the default fragment
    setFragment(FragmentMainHome.getInstance());
}

private void setFragment(Fragment fragment){
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.frame_layout, fragment);
    transaction.commit();
}

The code for FragmentAccount is:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    rootView = inflater.inflate(R.layout.fragment_activity_main_account, container, false);
    layout = rootView.findViewById(R.id.layout_fragment_main_account);

    etName = (EditText) layout.findViewById(R.id.etNameLabelValue);
    etEmail = (EditText) layout.findViewById(R.id.etEmailLabelValue);
    etGender = (EditText) layout.findViewById(R.id.etGenderLabelValue);
    etPhoneNumber = (EditText) layout.findViewById(R.id.etPhoneNumberLabelValue);

    btnEditAccount = (ImageButton) layout.findViewById(R.id.btnEditAccount);
    btnManageAddresses = (ImageButton) layout.findViewById(R.id.btnAccountManageAddresses);

    btnManageAddresses.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
        }
    });

    btnEditAccount.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
        }
    });

    return rootView;
}

The code for FragmentOrders is:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    rootView = inflater.inflate(R.layout.fragment_activity_main_order_history, container, false);
    layout = rootView.findViewById(R.id.layout_fragment_main_order_history);

    lvOrders = (ListView) layout.findViewById(R.id.lvOrders);
    tvNoOrdersFound = (TextView) layout.findViewById(R.id.tvNoOrdersFound);

    final SwipeRefreshLayout pullToRefresh = rootView.findViewById(R.id.swipe_refresh_layout_order_history);
    pullToRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            // load orders
            pullToRefresh.setRefreshing(false);
        }
    });

    lvOrders.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
        }
    });

    return rootView;
}

and similar kind of code goes for FragmentHome

The Problem

I can move between fragments and the view works fine. Now from Account fragment, I move to AccountEditActivity I do some update there and come back to MainActivity by pressing hardware back button

FragmentHome is displayed fine but when I click on FragmentAccount, screen goes blank

Now, if I click on Home fragment and click FragmentAccount again, it displays fine.

What is wrong here?

Answer 1

better use viewpager in your activity to show the fragments it's easy to manage while using viewpagers

have a look at the link Fragments in viewpager

and in your case just move this code from onCreate to onResume

setFragment(FragmentMainHome.getInstance());

for understanding better have a look at the lifecycle of activity in android

Activity life cycle