Get the current fragment object

In my main.xml I have

  <FrameLayout
        android:id="@+id/frameTitle"
        android:padding="5dp"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:background="@drawable/title_bg">
            <fragment
              android:name="com.fragment.TitleFragment"
              android:id="@+id/fragmentTag"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content" />

  </FrameLayout>

And I'm setting fragment object like this

FragmentManager fragmentManager = activity.getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment newFragment = new FragmentType1();
fragmentTransaction.replace(R.id.frameTitle, casinodetailFragment, "fragmentTag");

// fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();

It is setting different types of Fragment objects (FragmentType2,FragmentType3,...) at different time. Now at some point of time I need to identify which object is currently there.

In short I need to do something like this:

Fragment currentFragmen开发者_如何学编程t = //what is the way to get current fragment object in FrameLayout R.id.frameTitle

I tried the following

TitleFragment titleFragmentById = (TitleFragment) fragmentManager.findFragmentById(R.id.frameTitle);

and

    TitleFragment titleFragmentByTag = (TitleFragment) fragmentManager.findFragmentByTag("fragmentTag");

But both the objects (titleFragmentById and titleFragmentByTag ) are null

Did I miss something?

I'm using Compatibility Package, r3 and developing for API level 7.

findFragmentById() and findFragmentByTag() will work if we have set fragment using fragmentTransaction.replace or fragmentTransaction.add, but will return null if we have set the object at xml (like what I have done in my main.xml). I think I'm missing something in my XML files.

Now at some point of time I need to identify which object is currently there

Call findFragmentById() on FragmentManager and determine which fragment is in your R.id.frameTitle container.

If you are using the androidx edition of Fragment — as you should in modern apps — , use getSupportFragmentManager() on your FragmentActivity/AppCompatActivity instead of getFragmentManager()

Try this,

Fragment currentFragment = getActivity().getFragmentManager().findFragmentById(R.id.fragment_container);

this will give u the current fragment, then you may compare it to the fragment class and do your stuffs.

    if (currentFragment instanceof NameOfYourFragmentClass) {
     Log.v(TAG, "find the current fragment");
  }

I think you can use onAttachFragment event may be useful to catch which fragment is active.

@Override
public void onAttachFragment(Fragment fragment) {
    // TODO Auto-generated method stub
    super.onAttachFragment(fragment);

    Toast.makeText(getApplicationContext(), String.valueOf(fragment.getId()), Toast.LENGTH_SHORT).show();

}

I think you should do:

Fragment currentFragment = fragmentManager.findFragmentByTag("fragmentTag");

The reason is because you set the tag "fragmentTag" to the last fragment you have added (when you called replace).

You can get the list of the fragments and look to the last one.

    FragmentManager fm = getSupportFragmentManager();
    List<Fragment> fragments = fm.getFragments();
    Fragment lastFragment = fragments.get(fragments.size() - 1);

But sometimes (when you navigate back) list size remains same but some of the last elements are null. So in the list I iterated to the last not null fragment and used it.

    FragmentManager fm = getSupportFragmentManager();
    if (fm != null) {
        List<Fragment> fragments = fm.getFragments();
        if (fragments != null) {
            for(int i = fragments.size() - 1; i >= 0; i--){
                Fragment fragment = fragments.get(i);
                if(fragment != null) {
                    // found the current fragment

                    // if you want to check for specific fragment class
                    if(fragment instanceof YourFragmentClass) {
                        // do something
                    }
                    break;
                }
            }
        }
    }

This is the simplest solution and work for me.

1.) you add your fragment

ft.replace(R.id.container_layout, fragment_name, "fragment_tag").commit();

2.)

FragmentManager fragmentManager = getSupportFragmentManager();

Fragment currentFragment = fragmentManager.findFragmentById(R.id.container_layout);

if(currentFragment.getTag().equals("fragment_tag"))

{

 //Do something

}

else

{

//Do something

}

It might be late but I hope it helps someone else, also @CommonsWare has posted the correct answer.

FragmentManager fm = getSupportFragmentManager();
Fragment fragment_byID = fm.findFragmentById(R.id.fragment_id);
//OR
Fragment fragment_byTag = fm.findFragmentByTag("fragment_tag");

Maybe the simplest way is:

public MyFragment getVisibleFragment(){
    FragmentManager fragmentManager = MainActivity.this.getSupportFragmentManager();
    List<Fragment> fragments = fragmentManager.getFragments();
    for(Fragment fragment : fragments){
        if(fragment != null && fragment.getUserVisibleHint())
            return (MyFragment)fragment;
    }
    return null;
}

It worked for me

You can create field in your parent Activity Class:

public class MainActivity extends AppCompatActivity {

    public Fragment fr;

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

}

And then inside each fragment class:

public class SomeFragment extends Fragment {

@Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) {

        ((MainActivity) getActivity()).fr = this;
}

Your 'fr' field is current fragment Object

It's working also with popBackStack()

I know it's been a while, but I'll this here in case it helps someone out.

The right answer by far is (and the selected one) the one from CommonsWare. I was having the same problem as posted, the following

MyFragmentClass fragmentList = 
            (MyFragmentClass) getSupportFragmentManager().findFragmentById(R.id.fragementID);

kept on returning null. My mistake was really silly, in my xml file:

<fragment
    android:tag="@+id/fragementID"
    android:name="com.sf.lidgit_android.content.MyFragmentClass"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
/>

The mistake was that I had android:tag INSTEAD OF android:id.

1. Do a check (which fragment in the activity container) in the onStart method;

   @Override
   protected void onStart() {
   super.onStart();
   Fragment fragmentCurrent = getSupportFragmentManager.findFragmentById(R.id.constraintLayout___activity_main___container);
   }
   

2. Some check:

   if (fragmentCurrent instanceof MenuFragment) 
   

@Hammer response worked for me, im using to control a floating action button

final FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View view) {
            android.app.Fragment currentFragment = getFragmentManager().findFragmentById(R.id.content_frame);
            Log.d("VIE",String.valueOf(currentFragment));
            if (currentFragment instanceof PerfilFragment) {
                PerfilEdit(view, fab);
            }
        }
});

If you are extending from AbstractActivity, you could use the getFragments() method:

for (Fragment f : getFragments()) {
    if (f instanceof YourClass) {
        // do stuff here
    }
}

If you are defining the fragment in the activity's XML layour then in the Activity make sure you call setContentView() before calling findFragmentById().

If you are using the BackStack...and ONLY if you are using the back stack, then try this:

rivate Fragment returnToPreviousFragment() {

    FragmentManager fm = getSupportFragmentManager();

    Fragment topFrag = null;

    int idx = fm.getBackStackEntryCount();
    if (idx > 1) {
        BackStackEntry entry = fm.getBackStackEntryAt(idx - 2);
        topFrag = fm.findFragmentByTag(entry.getName());
    }

    fm.popBackStack();

    return topFrag;
}

This will give you the current fragment class name -->

String fr_name = getSupportFragmentManager().findFragmentById(R.id.fragment_container).getClass().getSimpleName();

you can check which fragment is currently loaded by this

        supportFragmentManager.addOnBackStackChangedListener {
        val myFragment = supportFragmentManager.fragments.last()

        if (null != myFragment && myFragment is HomeFragment) {
            //HomeFragment is visible or currently loaded
        } else {
            //your code
        }
    }

I use the following function in Kotlin:

supportFragmentManager.fragments.run {
    getOrNull(size - 1)?.let { currentFragment ->
        ...
    }
}

I recently worked on an activity involving multiple fragments so thought to share the method I used here:

Firstly, I declared a function getCurrentFragment() which returned me, yeah you guessed it, the current fragment, lol.

private fun getCurrentFragment(): Fragment? {
    return supportFragmentManager.findFragmentById(R.id.fragmentContainerView)
}

Then I override the onBackPressed function in the activity to define the navigation within fragments. Suppose, I wanted to show fragment 2 if user is in fragment 3 and presses back so I did something like this to achieve this

override fun onBackPressed() {
        if (getCurrentFragment() is Fragment3) {
            showFragment2()
        } else {
            super.onBackPressed()
        }
    }

And in showFragment2() I did something like this:

private fun showFragment2() {
        val fragment = Fragment2.newInstance()
        supportFragmentManager.commit {
            replace(R.id.FragmentContainerView, fragment, "Add a tag here")
        }
    }

I think this should give better idea to people looking on how to navigate through fragments within an activity.