Develop Reference

Android - Call a fragment inside tab

I try to create an application that has two pages. First page is a tabbed page and second page is a detail page.
I create a tapped page using this guide. I have a mainactivity that contains view pager and 3 tabs(Tab1, Tab2, Tab3). Tab3 contains a button to navigate detail page. Each tab has own .java(extends Fragment) and .xml file. I edit fragmentThree.xml layout :
<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:id="#+id/fragmentThree"]>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/goToDetail"
android:text="GO TO DETAIL" />
I create a new fragment for detail page. I set onclick method inside of Tab3.java;
goToDetail.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.mainActivity, new Detail());
transaction.commit();
}
});
When I press the button, it doesn't do anything. I don't replace the fragment.

Use you viewpager id instead of main layout id, where you set the tab layout fragment.
transaction.replace(R.id.viewpager, new Detail());

use Frame layout in Main Activity
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/parent">
In clicklistiner :-
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.parent, new Detail());
transaction.commit();

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 Fragment transaction - replacing fragment leaves the old one with strange state

I have strange behaviour. Every time i replace the same type of fragment in Activity (using transaction), the new Fragment instance is added to Fragment List. The old instances remains active in Fragment Manager and after orientation change are visible on the screen (although not clickable).
My Activity Layout:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
-->
<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<android.support.v4.widget.DrawerLayout
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.cubesoft.zenfolio.moments.app.activity.MainActivity" >
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</FrameLayout>
<fragment
android:id="#+id/navigation_drawer"
android:name="com.cubesoft.zenfolio.moments.app.fragment.NavigationDrawerFragment"
android:layout_width="#dimen/navigation_drawer_width"
android:layout_height="match_parent"
android:layout_gravity="start"
tools:layout="#layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
<fragment
android:id="#+id/fragmentConnectionStatus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
class="com.cubesoft.zenfolio.fragment.ConnectionStatusFragment" />
My code that changes fragments:
#Override
public void onNavigationDrawerItemSelected(int position) {
mCurrentDrawerPosition = position;
// update the main content by replacing fragments
List<Fragment> fragmemts = getSupportFragmentManager().getFragments();
switch (position) {
case 0:{
if ( getMyApplication().getGroupModel().getUsersCount() > 0 ) {
final Fragment fragment = UserSelectionFragment.newInstance();
final FragmentManager fragmentManager = getSupportFragmentManager();
//fragmentManager.popBackStack();
final FragmentTransaction tr = fragmentManager
.beginTransaction();
tr.replace(R.id.container, fragment);
tr.addToBackStack(null);
tr.setCustomAnimations(R.anim.abc_fade_in, R.anim.abc_fade_out);
tr.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
tr.commit();
} else {
final Fragment fragment = MomentsFragment.newInstance(mUsername);
final FragmentManager fragmentManager = getSupportFragmentManager();
//fragmentManager.popBackStack();
final FragmentTransaction tr = fragmentManager
.beginTransaction();
tr.replace(R.id.container, fragment);
//tr.setCustomAnimations(R.anim.abc_fade_in, R.anim.abc_fade_out);
tr.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
tr.addToBackStack(null);
tr.commit();
}
break;
}
case 1: {
final Fragment fragment = DownloadFragment.newInstance();
final FragmentManager fragmentManager = getSupportFragmentManager();
//fragmentManager.popBackStack();
final FragmentTransaction tr = fragmentManager
.beginTransaction();
tr.replace(R.id.container, fragment);
tr.addToBackStack(null);
tr.commit();
break;
}
/*case 2:
fragment = UserSelectionFragment.newInstance();
break;*/
}
}
The UserSelectionFragment is displayed incorrectly after several orientation changes, old instances of UserSelectionFragment remains in Fragment List but their View objects are null.
What is wrong?

Try removing
tr.addToBackStack(null);
To me this adds your frgament to the backstack and thats the reason why they are kept in your fragment list. Their view are null because they have been destroyed before going to backgroud.

How can I add a fragment from within a viewpager that covers the viewpager tabs

Currently I have a viewpager setup according to the documentation. Within the first fragment tab I have setup a recycler view that contains a list of cardviews. Within each cardview I have a button which should open a new fragment. I would like this new fragment to overlap the action bar tabs (something similiar to how facebook comments work when you click the comment button). I am not sure how to get it working. I created an extra framelayout and relative layout above my viewpager hoping that it would overlap, however this doesn't seem to work. How can I have my new fragment cover the action bar tabs as well? I am not asking how to replace the current viewpager fragment if that makes sense.
I filled the new fragment with a red background, the result after envoking the onclick listener is shown here: http://i.imgur.com/yHYpzGr.png
In my onclick listener I have:
FragmentManager fragmentManager = activity.getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.container, commentFragment,"comment_fragment_tag");
fragmentTransaction.commit();
My main activity layout that contains the viewpager:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="#+id/main_activity">
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
</FrameLayout>

Try this .. hope it works
FragmentManager fragmentManager = activity.getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, commentFragment,"comment_fragment_tag");
fragmentTransaction.commit();
or
Fragment fr = new FragmentTwo() ;
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.container, fr);
ft.commit();
hear fr is the new fragment that would be replaced

Fragment not added to backstack

I'm having trouble with getting Fragments and the backstack to work.
I've got a layout with a FrameLayout for holding various fragments and another fragment:
<LinearLayout
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/filterableListContainer"
android:layout_weight="50">
</FrameLayout>
<fragment class="com.facetoe.remotempd.fragments.PlayerBarFragment"
android:id="#+id/playerBarFragment"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:layout="#layout/player_bar"/>
</LinearLayout>
When I start the Activity that uses this layout I add the fragment to the FrameLayout like so:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
if (findViewById(R.id.filterableListContainer) != null) {
// However, if we're being restored from a previous state,
// then we don't need to do anything and should return or else
// we could end up with overlapping fragments.
if (savedInstanceState != null) {
return;
}
// Create a new Fragment to be placed in the activity layout
ArtistListFragment listFragment = new ArtistListFragment();
// Add the fragment to the 'fragment_container' FrameLayout
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.filterableListContainer, listFragment);
ft.addToBackStack(null);
ft.commit();
} else {
Log.e(TAG, "Couldn't find filterableListFragment");
}
}
When the user clicks an item, I attempt to replace the fragment with this code:
ArtistAlbumsListFragment fragment = new ArtistAlbumsListFragment(getActivity(), albums);
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.filterableListContainer, fragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
However when I press the back button I get returned to the home screen. Can anyone tell me where I'm going wrong?

Ok I fixed it. When I created the Activity in Intellij it created a subclass of ActionBarActivity. Removing ActionBarActivity and replacing it with Activity made the fragments transitions work as expected.

Dont add ft.addToBackStack(null) this statement.
ArtistAlbumsListFragment fragment = new ArtistAlbumsListFragment(getActivity(), albums);
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.filterableListContainer, fragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.commit();