I was trying to implement the bottom navigation with fragment inside an activity.
I have done that and it was successful.
To replace the fragment on click each navigation item, I use the following code.
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_notifications:
loadFragment(new NotificationsFragment());
return true;
case R.id.navigation_notes:
loadFragment(new NotesFragment());
return true;
case R.id.navigation_about:
loadFragment(new AboutFragment());
return true;
}
return false;
}
};
private void loadFragment(Fragment fragment) {
// load fragment
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
Now the problem is that when I click on a navigation in the bottom navigation bar multiple times, the fragment is also getting added to the back stack multiple times.
So when I click the back button the fragment is again loaded, not exiting or loading the previous fragment.
So, How can I prevent the fragment getting added to the back stack multiple times?
Remove
transaction.addToBackStack(null);
or add
transaction.disallowAddToBackStack();
Related
I have a setup of 3 Fragments inside my main activity and want to navigate them using the BottomNavigationView. I want to add them once and then just switch between them without actually destroying the Fragments. Everything works fine except that the first fragment added to the SupportFragmentManager always disappears (tried changing the order so the problem is not with the Fragments themselves). Actually, it doesn't disappear but the last Fragment that occupied the container shows up.
Eg. I go to position 3, Fragment 3 shows up in the container and then click on position 1, Fragment 3 will still occupy the container. But if I tap position 2 Fragment 2 will appear. How I'm adding the Fragments:
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.container, fragment1); //whatever gets added here ends up being invisible
ft.commitAllowingStateLoss();
ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.container, fragment2);
ft.commitAllowingStateLoss();
ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.container, fragment3);
ft.commitAllowingStateLoss();
How I'm switching between them using the OnNavigationItemSelectedListener:
private BottomNavigationView.OnNavigationItemSelectedListener navigation_listener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
Fragment previousFragment = getSupportFragmentManager().findFragmentById(R.id.container);
switch(item.getItemId()){
case R.id.bottom_navigation_bar_position1:
selectedFragment = fragment1;
break;
case R.id.bottom_navigation_bar_position2:
selectedFragment = fragment2;
break;
case R.id.bottom_navigation_bar_position3:
selectedFragment = fragment3;
break;
}
getSupportFragmentManager().beginTransaction().hide(previousFragment).commit();
getSupportFragmentManager().beginTransaction().show(selectedFragment).commit();
return true;
}
};
The XML menu navigation:
<item
android:id="#+id/bottom_navigation_bar_position1"
android:title="Title1"
android:icon="#drawable/ic1"
/>
<item
android:id="#+id/bottom_navigation_bar_position2"
android:title="Title2"
android:icon="#drawable/ic2"
/>
<item
android:id="#+id/bottom_navigation_bar_position3"
android:title="Title3"
android:icon="#drawable/ic3"
/>
Btw. just using replace() instead of show and hide works but that's not the goal...
I've also tested whether the first added Fragment exits (and doesn't get destroyed) and it indeed exists...
Thanks!
Instead of trying to show and hide fragment I solved the problem by managing the Fragments using a ViewPager and a SectionsPageAdapter. Once you link these two, use ViewPager.setOffscreenPageLimit(3) to make sure no Fragments get destroyed. My BottomNavigationView.OnNavigationItemSelectedListener looks like this now:
private BottomNavigationView.OnNavigationItemSelectedListener navigation_listener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch(item.getItemId()){
case R.id.bottom_navigation_bar_position1:
tab_view_pager.setCurrentItem(0);
return true;
case R.id.bottom_navigation_bar_position2:
tab_view_pager.setCurrentItem(1);
return true;
case R.id.bottom_navigation_bar_position3:
tab_view_pager.setCurrentItem(2);
return true;
}
return false;
}
};
You have to set 0th position item selected for BottomNavigationView.OnNavigationItemSelectedListener. Find Menu bottom_navigation_bar_position1
I used this in my code, please refactor according to your needs
BottomNavigationView navigation = findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(this);
Menu menu = navigation.getMenu();
this.onNavigationItemSelected(menu.findItem(R.id.navigation_doc));
I'm currently developing a Android studio App using fragment and a bottom navigation bar.
When I click on a navigation bar's item, it's replacing the current fragment by another one which correspond the fragment I wanted for this item.
The problem is, the objects in my fragment are all reset after replacing fragment.
I'm not removing the fragment from the container so I don't really understand why all the objects are reset after doing this.
Here is my code to add and replace fragment to my FrameLayout :
private void setFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(android.R.anim.slide_in_left, android.R.anim.fade_out);
if (getSupportFragmentManager().findFragmentById(R.id.main_frame) == null) {
fragmentTransaction.add(R.id.main_frame, fragment);
}
else
{
fragmentTransaction.replace(R.id.main_frame, fragment);
}
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
and here is the bottom navigation bar code to execute the previous function and change the displayed fragment:
homeFragment = new HomeFragment();
programFragment = new ProgramFragment();
bluetoothFragment = new BluetoothFragment();
mMainNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
test = mMainNav.getMenu().getItem(2);
switch (item.getItemId()) {
case R.id.nav_home:
//mMainNav.setItemBackgroundResource(R.color.colorPrimary);
HQ_logo_IV.setVisibility(View.VISIBLE);
setFragment(homeFragment);
return true;
case R.id.nav_program:
//mMainNav.setItemBackgroundResource(R.color.colorAccent);
HQ_logo_IV.setVisibility(View.INVISIBLE);
setFragment(programFragment);
return true;
case R.id.nav_bluetooth:
//mMainNav.setItemBackgroundResource(R.color.colorPrimaryDark);
HQ_logo_IV.setVisibility(View.INVISIBLE);
setFragment(bluetoothFragment);
return true;
default:
return false;
}
}
});
I found the way to stop this thing.
I used an AsyncTask to refresh my fragment state.
I just put new "yourAsyncTaskName"().execute() at the beginning of my onCreate() method to refresh the fragment when it's created or replaced.
Hope this will help.
I have Base Activity including NavigationView with 2 menu items. On start it loads Home fragment having background image inside it. Each loads specific fragment. When I select Terms & Conditions menu item, it loads T&C fragment & when I press back button it simply kills it.
However, when I select About Us menu item, it loads About Us fragment but I need to press BACK button twice to kill it. I need to know why does it happen?
Part of Code in AppBaseActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
fragmentManager = getSupportFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
HomeFragment homeFragment = new HomeFragment();
fragmentTransaction.add(R.id.body_container, homeFragment, "");
fragmentTransaction.commit();
}
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
navigationView.getMenu().findItem(item.getItemId()).setChecked(true);
switch (item.getItemId()) {
case R.id.nav_terms :
fragmentTransaction = fragmentManager.beginTransaction();
TCFragment tcFragment = new TCFragment();
fragmentTransaction.replace(R.id.body_container, tcFragment, "");
fragmentTransaction.commit();
break;
case R.id.nav_about_us :
fragmentTransaction = fragmentManager.beginTransaction();
AboutUsFragment aboutUsFragment = new AboutUsFragment();
fragmentTransaction.replace(R.id.body_container, aboutUsFragment, "");
fragmentTransaction.commit();
break;
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
All fragments simply have overridden onCreateView() by inflating respected xml only. No code is written in both fragments yet.
You can stop back hardware navigation if you want.
Simply using onBackPressed() without super.onBackPressed()
#Override
public void onBackPressed() {
}
#Override
public void onBackPressed() {
super.onBackPressed();
}
Hi guys here is my code
navigationView.setNavigationItemSelectedListener(new NavigationView
.OnNavigationItemSelectedListener() {
#Override public boolean onNavigationItemSelected(#NonNull MenuItem item) {
if (item.isChecked()) {
//item already selected. Do nothing
drawerLayout.closeDrawer(GravityCompat.START);
return true;
}
switch (item.getItemId()) {
case R.id.home:
FragmentTransaction transaction = getSupportFragmentManager()
.beginTransaction();
transaction.replace(R.id.fragment, new HomeFragment())
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).commit();
break;
case R.id.other:
transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment, new OtherFragment())
.addToBackStack(null).setTransition(FragmentTransaction
.TRANSIT_FRAGMENT_FADE).commit();
break;
default:
break;
}
drawerLayout.closeDrawer(GravityCompat.START);
return true;
}
});
I basically only have 2 fragments and merely the HomeFragment should be added to the backstack. After switching between HomeFragment and OtherFragment for a while and clicking on the back button while on the HomeFragment, I end up with the HomeFragment getting displayed several times.
Within the HomeFragment lies a recyclerview. When I scroll up and down I can really see that the rows are displayed multiple times.
How can I make sure that the HomeFragment is added to the backstack only once.
Thanks
You could easily check your fragment with
YourFragment.isAdded
And if you have a multiple fragment you could create a new class to manage all the fragment and create state to check if fragment have been added or not.
When you click on the Home menu item try to find out whether there is any fragment in the backstack or not. If yes, call popBackStack() or replace a fragment as you do now otherwise. Use this code: if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
getSupportFragmentManager().popBackStack();
}
I have an app which utilized NavigationDrawer and toolbar. When I click on one of the menu in the NavigationDrawer, it displays a fragment (let's call it fragment1). Inside fragment1 is a button, when clicked would display another fragment (fragment2).
Ok so when I'm at fragment1, the toolbar would display a hamburger icon, where when I click on it, the drawer would be opened. And when I'm at fragment2, the toolbar would display a back icon (up caret) instead of the hamburger. Ok this is correct, but when I click on the back icon (up caret) the drawer would be opened instead. So what should I do so that when the back icon (up caret) is clicked, I'd be brought back to fragment1, and not opening the drawer?
This is my onClick for the drawer
#Override
public void onClick(View v) {
int position = getPosition();
Fragment fragment = null;
FragmentManager fManager = ((FragmentActivity) contxt).getSupportFragmentManager();
FragmentTransaction transaction = fManager.beginTransaction();
Toast.makeText(contxt, "The Item Clicked isss: " + position, Toast.LENGTH_SHORT).show();
mDrawerLayout = (DrawerLayout) ((FragmentActivity) contxt).findViewById(R.id.dlMainDrawer);
mDrawerLayout.closeDrawers();
switch (position) {
case 1:
fragment = new MenuHome();
transaction.replace(R.id.container, fragment, "fragmentHome");
transaction.addToBackStack(null);
transaction.commit();
break;
case 2:
fragment = new MenuExpensesDaily();
transaction.replace(R.id.container, fragment, "fragmentExpensesDaily");
transaction.addToBackStack(null);
transaction.commit();
break;
default:
break;
}
}
So using the code above, I opened an instance of MenuExpensesDaily. And inside MenuExpensesDaily, when I click on a menu item, it would open another fragment, ExpensesDailyAdd, as shown below:
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.menu_main, menu);
MenuItem mItem = menu.findItem(R.id.tbAddExpenses);
mItem.setVisible(true);
mItem.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
#Override
public boolean onMenuItemClick(MenuItem item) {
ExpensesDailyAdd addExpenses = new ExpensesDailyAdd();
getFragmentManager().beginTransaction()
.replace(R.id.container, addExpenses, null)
.addToBackStack(null)
.commit();
return true;
}
});
}
Ok so now when ExpensesDailyAdd is opened, the hamburger icon is changed to the up caret. But when I click the up caret, it opens the drawer instead of going back to the previous fragment.