getSupportFragmentManager().findFragmentById retur

Question

What I am doing: updating UI (Fragment UI) from Broadcast Receiver. But while finding Fragment I am getting null in return.

OnReceive (Broadcast Receiver):

 if(MainActivity.getInstace()!=null){
                MainActivity.getInstace().updateUI();
            }

MainActivity.class (Fragment Activity):

     public void updateUI() {
            MainActivity.this.runOnUiThread(new Runnable() {
                public void run() {

//getting null here 
                    SlidingTab frag = (SlidingTab)getSupportFragmentManager().findFragmentByTag("slidingtab");
                    frag.updateUI();
                }
            });
        } 

Code for calling Fragment from Activity:

 FragmentManager fragmentManager = getSupportFragmentManager();
                FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                fragmentManager.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);


                ft.setCustomAnimations(R.anim.glide_fragment_horizontal_in, R.anim.glide_fragment_horizontal_out);
                ft.replace(R.id.content_frame1, new SlidingTab(), "slidingtab");
                ft.addToBackStack("slidingtab");
                // Start the animated transition.
                ft.commit();
                break;

SlidingTab.class (Fragment UI update code ):

public class SlidingTab extends Fragment {
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.sliding_tab, container, false);}
    public void updateUI(){

                badge.setVisibility(View.VISIBLE);
    }
            }

Fragment (SlidingTab.xml)

<LinearLayout 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:id="@+id/frame_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:orientation="vertical"
    tools:context="com.RareMediaCompany.BDTrial.SlidingTab">

    <include
        android:id="@+id/toolbar1"
        layout="@layout/toolbar_job" />

    <com.RareMediaCompany.BDTrial.Utils.CustomTabLayout
        android:id="@+id/sliding_tabs"
        style="@style/CustomTabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#eeeeee"
        app:tabIndicatorColor="#f39220"
        app:tabIndicatorHeight="3dp"
        app:tabMaxWidth="0dp"
        app:tabMode="fixed"
        app:tabPaddingEnd="0dp"
        app:tabPaddingStart="0dp"
        app:tabTextAppearance="@android:style/TextAppearance.Widget.TabWidget"
        app:tabSelectedTextColor="#808080" />

    <LinearLayout
        android:id="@+id/linear1"
        android:background="@android:color/white"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:layout_marginRight="8dp"
        android:layout_marginLeft="5dp"
        android:orientation="horizontal"
        android:weightSum="1">

        <android.support.v7.widget.SearchView
        android:layout_width="300dp"
        android:layout_height="45dp"
        android:id="@+id/searchView"
        android:layout_weight="1"
        android:layout_gravity="center"
            android:layout_marginEnd="5dp"
            android:clickable="true"
        style="@style/CitySearchView"
        android:background="@drawable/searchview"
        android:layout_marginLeft="5dp"/>

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:weightSum="1"
            android:orientation="horizontal">

        <LinearLayout
            android:id="@+id/list_linearlayout"
            android:layout_width="45dp"
            android:layout_height="45dp"
            android:layout_weight="0.5"
            android:layout_gravity="center"
            android:background="#f39220">
        <!--android:background="#75aadb">-->
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="2dp"
                android:layout_weight="0.3"
                android:src="@drawable/listicon"/>

        </LinearLayout>

        <LinearLayout
            android:id="@+id/maplist"
            android:layout_width="45dp"
            android:layout_height="45dp"
            android:layout_gravity="center"
            android:layout_weight="0.5"
            android:background="#75aadb">
            <ImageView
                android:layout_width="20dp"
                android:layout_height="wrap_content"
                android:layout_marginTop="2dp"
                android:layout_marginRight="3dp"
                android:layout_weight="0.3"
                android:src="@drawable/map_icon_1"/>

        </LinearLayout>
        </LinearLayout>

    </LinearLayout>
        <!--android:layout_width="320dp"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:layout_marginLeft="10dp"-->
        <!--android:layout_marginTop="10dp"-->
        <!--android:id="@+id/searchview"/>-->

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@android:color/white" />

</LinearLayout>

The fragment (SlidingTab) consist of textviews and viewpager . And i am not able to find it in MainActivity.class. Every time i call
SlidingTab frag = (SlidingTab)getSupportFragmentManager().findFragmentByTag("slidingtab") Frag comes null.

Answer 1

Use getSupportFragmentManager().executePendingTransactions() after fragment transaction. After calling this method you can get the fragment using both findFragmentById() and findFragmentByTag() methods.

Also make sure you pass Valid Id or Tag for the fragment.