Develop Reference

When navigating from one fragment to another, the second fragment overlaps

On the click of a button I want to navigate from one fragment to another. The problem is that when I press the button the second fragment overlaps the other.
I searched for some answers but it doesn't seem to word in my case. I tried adding a background color but it still overlaps.
So after I click the button the following thing happens:
Here are my codes:
I gave the first fragment an ID:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.home.HomeFragment"
android:background="#FFF">
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="1dip"
app:layout_constraintBottom_toTopOf="parent"
android:background="#FFF"/>
The ID of the button is: nextFragment
The code inside the class of the first fragment is:
nextFragment = v.findViewById(R.id.nextFragment);
nextFragment.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v){
Fragment fragment = new NotificationsFragment();
FragmentManager fragmentManager = getParentFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.fragment_container, fragment)
.addToBackStack(null)
.commit();
}
});
Hope i gave enough information, if not don't hesitate to ask for more! Thanks in advance.

The problem is that you are using fragment_container as the first fragment instead of the container for your first fragment.
In your MainActivity you have to load your first fragment inside that container. Not use it as a fragment.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(savedInstanceState == null) {
Fragment firstFragment = new YourFirstFragment();
FragmentManager manager = getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.fragment_container, firstFragment);
transaction.commit();
}
}
After that, in your first fragment, when you will replace the fragment it will work great.

So the solution was simple.. I gave an Id to a framelayout inside the first fragment instead of to the root layout.
Now the next thing is that the tab on the bottom also has to change when the button is pressed.

Fragment to fragment to fragment get crash

I have a main activity , it contains lots of fragments.
Main activity layout looks like this:
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/drawerLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.user.taiwandigestionsociety_v11.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#FFFFFF">
<include layout="#layout/toolbar"/>
//switch fragment over here
<FrameLayout
android:id="#+id/mainFrame"
android:layout_gravity="end"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</android.support.design.widget.AppBarLayout>
<android.support.design.widget.NavigationView
android:id="#+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#android:color/transparent"
android:fitsSystemWindows="true"
app:headerLayout="#layout/nav_header">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
and I click the drawer item it will change to first fragment:
#Override
public void onClick(View view) {
int id = view.getId();
if (id == R.id.activitiesContents) {
//change to first fragment successful
switchFragment(ActivityList.newInstance());
toolbar.setTitle(R.string.activitiesContents);
drawerLayout.closeDrawer(GravityCompat.START);
}
}
my switch fragment function:
public void switchFragment(Fragment fragment) {
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.mainFrame, fragment, null);
//transaction.addToBackStack(null);
transaction.commit();
}
then i click the button in first fragment, it changes to second fragment too:
//take me to second fragment succeed
switchFragment(ActivityHomePage.newInstance());
finally i click the button in second fragment, it crashed
//i want to switch to third fragment , just the same with previous
switchFragment(NewsInformation.newInstance());
the error log:
Why i got crash when i switch to third fragment? I completely have no clue.
I found the crash function function , because I set the class:
public class CommonSwitch extends Fragment {
//switch Fragment
public void switchFragment(Fragment fragment) {
FragmentManager manager = getActivity().getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.mainFrame, fragment, null);
//transaction.addToBackStack(null);
transaction.commit();
}
}
and I try to call it new CommonSwitch.switchFragment(goToFragment);
now I have set public void switchFragment every Fragment class.
Why when I set new CommonSwitch will cause crash ?

Your Activity state is Not Maintain.
On second layer use Activity instead of Fragment . Follow Android Standards.
According to standards Third Fragment should be Activity. otherwise you have to maintain MainActivity state.
Thanks

Android- FragmentTransaction.replace() works only once

I'm using a navigation drawer along with a SwipeRefreshLayout for the main content and when the user selects a menu item in the navigation drawer, I want to replace the fragment inside the SwipeRefreshLayout with another fragment.
This is what my onNavigationItemSelected() looks like:
// Handle navigation view item clicks here.
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
selectedNavItem = item.getItemId();
if(selectedNavItem == R.id.nav_files){
filesFragment = new FilesFragment();
fm = getSupportFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
transaction.replace(R.id.swipeLayout,filesFragment,"files");
transaction.commit();
} else if(selectedNavItem == R.id.nav_accounts){
accountsFragment = new AccountsFragment();
fm = getSupportFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
transaction.replace(R.id.swipeLayout,accountsFragment,"accounts");
transaction.commit();
}
return true;
But this never works. When I click an item in the nav drawer, the fragment is replaced by a blank screen. My onCreate method also uses FragmentTransaction.replace() but that seems to work fine.
I also tried FragmentTransaction.remove() and then FragmentTransaction.add() but even that doesn't seem to work.
Edit: Layout files:
Layout of the content view of the navigation drawer:
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.harshallele.cloudpool.MainActivity"
tools:showIn="#layout/app_bar_main"
android:id="#+id/swipeLayout">
</android.support.v4.widget.SwipeRefreshLayout>
This is included inside another layout file which contains a CoordinatorLayout containing the toolbar.That file, in turn, is inside the main layout file of the activity inside a android.support.v4.widget.DrawerLayout
(Basically, this is the Navigation Drawer Activity provided by Android Studio when adding an Activity)
Layout for FilesFragment:
<FrameLayout 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"
tools:context=".fragments.FilesFragment">
<android.support.v7.widget.RecyclerView
android:id="#+id/fileListView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
/>
<ProgressBar
android:id="#+id/itemsLoadingProgress"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
style="?android:attr/progressBarStyleHorizontal"
android:indeterminateOnly="true"
android:visibility="invisible"
/>
</FrameLayout>
Layout for AccountsFragment(this is just the default blank fragment, because i haven't finished this yet):
<FrameLayout 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"
tools:context="com.harshallele.cloudpool.fragments.AccountsFragment">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/hello_blank_fragment" />
</FrameLayout>
Edit 2:
AccountsFragment:
public class AccountsFragment extends Fragment {
public AccountsFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_accounts, container, false);
}
}

With just this bit of code we can't help you so much. The problem can be that:
The FilesFragment and AccountsFragment aren't initialized in the right way;
The Layout with id swipeLayout can have visibility = gone;
The Layout of FilesFragment and AccountsFragment can be empty;
This are just some of the infinite reason why your code doesn't work properly so please share more code about the two Fragments and relative XML.

Back Button with strange behaviour on fragments

Here's my navigation:
HomeFragment -> LoginFragment -> CreateEventFragment
My HomeFragment is my first Fragment inside my MainActivity.
In my code, I'm replacing each one of them using the same view id( a FrameLayout inside my MainActivity's layout: R.id.container).
So every replace() is being called like this:
FragmentManager fragmentManager = mContext.getSupportFragmentManager();
fragmentManager.beginTransaction()
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.replace(containerId, nextFragment).addToBackStack(null).commit();
Except for LoginFragment to CreateEventFragment, because after the user logs in, he doesn't have to go back to LoginFragment so I don't call addToBackStack().
But something strange is happening:
When I'm on CreateEventFragment, after logging in successfully, and press the back button, my CreateEventFragment onDestroy() is not being called.
Debugging it I noticed that it isn't removed from the backStack, what am I doing wrong?
EDIT
Some code:
Common replace fragment method, inside BaseFragment, parent class of all three Fragments
public void replaceFragment(int containerId, Fragment nextFragment, boolean addToBackStack){
FragmentManager fragmentManager = mContext.getSupportFragmentManager();
if (addToBackStack)
fragmentManager.beginTransaction()
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.replace(containerId, nextFragment).addToBackStack(null).commit();
else
fragmentManager.beginTransaction()
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.replace(containerId, nextFragment).commit();
}
On HomeFragment:
BaseFragment nextFragment =
(PreferencesHandler.isLogged()) ?
CreateEventFragment.newInstance() :
LoginFragment.newInstance("create_event") ;
replaceFragment(R.id.main_fragment_container, nextFragment, true);
On LoginFragment:
public void goToNextFragment(){
Fragment nextFragment;
switch (mIntent){
case "create_event":
nextFragment = new CreateEventFragment();
break;
case "participate":
nextFragment = new ListsFragment();
break;
default:
nextFragment = new HomeFragment();
break;
}
replaceFragment(R.id.main_fragment_container, nextFragment, false);
}
My MainActivity's layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<include
android:id="#+id/toolbar_actionbar"
layout="#layout/toolbar_actionbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:layout_below="#+id/toolbar_actionbar"
tools:context=".MainActivity">
<FrameLayout
android:id="#+id/main_fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/toolbar_actionbar"
/>
<fragment android:id="#+id/navigation_drawer"
android:layout_width="#dimen/navigation_drawer_width"
android:layout_height="match_parent"
android:layout_gravity="start"
android:name="Fragments.`NavigationDrawerFragment`"
tools:layout="#layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
</RelativeLayout>
EDIT 2
Noticed that pressing back button calls LoginFragment onDestroy, but not CreateFragment's. Also noticed that backStack has LoginFragment, guess it shouldn't, right?

fragment not shown on top in activity

i want to show a fragment when i click a item into my action bar, in code i do that:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.create_boundary:
Fragment boundary = new BoundaryFragment();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.map_activity, boundary);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack(null);
ft.commit();
break;
}
}
and the fragment:
public class BoundaryFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// create the view of the fragment associate with the maps activity
View view = inflater.inflate(R.layout.boundary_maps, container, false);
return view;
}
fragment's layout:
<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</GridLayout>
activity_map.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/map_activity"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<fragment
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />
</RelativeLayout>
onCreate of mapsActivity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
[...]
}
i don't understand why is not shown.Can someone tell me what's is wrong?
thanks in advance.

As stated in the official documentation for FragmentTransaction.replace(int,Fragment,String):
Parameters
- containerViewId Identifier of the container whose
fragment(s) are to be replaced.
- fragment The new fragment to place in
the container.
- tag Optional tag name for the fragment, to later
retrieve the fragment with FragmentManager.findFragmentByTag(String).
That means you are using the id in the transaction incorrectly. Also you may want to add the BoundaryFragment on top of the one defined in the XML layout, therefore you should use FragmentTrasaction.add(int, Fragment) instead.
To fix your problem anyway you should move your id to the RelativeLayout, as below:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/map_activity"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />
</RelativeLayout>

First, you are using a Fragment as it would be a ViewGroup. You’re trying to place a Fragment inside another Fragment when you perform the next statement:
ft.replace(R.id.map_activity, boundary);
Second, you can’t replace a fragment that has been defined in the layout file. You can only replace fragments that you added dynamically using FragmentTransaction.
To achieve what you want, take a look at the sample code under the section:
"Or, programmatically add the fragment to an existing ViewGroup."