// Tutorial //

Android Passing Data Between Fragments

Published on August 3, 2022
Default avatar
By Anupam Chugh
Developer and author at DigitalOcean.
Android Passing Data Between Fragments

While we believe that this content benefits our community, we have not yet thoroughly reviewed it. If you have any suggestions for improvements, please let us know by clicking the “report an issue“ button at the bottom of the tutorial.

In this tutorial, we’ll be developing an application that contains TabLayout, ViewPager and Fragments. We’ll implement a functionality that passes data from one Fragment to the other fragment.

Android Passing Data between Fragments

Intents are only usable for sending data on an Activity level. To pass data between fragments we need to create our own interfaces. The flow to send a String data from one Fragment to another is shown below. android passing data between fragments Let’s get started with the implementation of the above flow.

Android Passing Data between Fragments Project Structure

android sharing data between fragments The xml layout for the MainActivity.java class is given below.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:app="https://schemas.android.com/apk/res-auto"
    xmlns:tools="https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.journaldev.passingdatabetweenfragments.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            style="@style/MyStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabGravity="fill"
            app:tabMode="fixed" />

    </android.support.design.widget.AppBarLayout>


    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />


</android.support.design.widget.CoordinatorLayout>

The styles for the TabLayout and ToolBar are defined in the styles.xml file as shown below.

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

    <style name="MyStyle" parent="Widget.Design.TabLayout">
        <item name="tabIndicatorColor">#FFFF</item>
        <item name="tabIndicatorHeight">5dp</item>
        <item name="tabPaddingStart">8dp</item>
        <item name="tabPaddingEnd">8dp</item>
    </style>

</resources>

The ViewPagerAdapter.java is where the Fragments are initialised. The code is given below.

public class ViewPagerAdapter extends FragmentPagerAdapter {

    public ViewPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        Fragment fragment = null;
        if (position == 0) {
            fragment = new FragmentOne();
        } else if (position == 1) {
            fragment = new FragmentTwo();
        }
        return fragment;
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        String title = null;
        if (position == 0) {
            title = "Tab-1";
        } else if (position == 1) {
            title = "Tab-2";
        }
        return title;
    }
}

FragmentOne would be sending the data entered in EditText to FragmentTwo. The xml layout for fragment_one.xml is given below.

<?xml version="1.0" encoding="utf-8"?>

<ScrollView xmlns:android="https://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <EditText
            android:id="@+id/inMessage"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_above="@+id/btnPassData"
            android:layout_margin="16dp"
            android:hint="Enter here" />

        <Button
            android:id="@+id/btnPassData"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="PASS DATA TO FRAGMENT TWO" />


    </RelativeLayout>
</ScrollView>

The xml layout for fragment_two.xml is given below.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/txtData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:layout_centerInParent="true"
        android:text="No data received" />


</RelativeLayout>

The code for FragmentOne.java class is given below.

package com.journaldev.passingdatabetweenfragments;

import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;

public class FragmentOne extends Fragment {

    SendMessage SM;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View rootView = inflater.inflate(
                R.layout.fragment_one, container, false);
        return rootView;


    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        Button btnPassData = (Button) view.findViewById(R.id.btnPassData);
        final EditText inData = (EditText) view.findViewById(R.id.inMessage);
        btnPassData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SM.sendData(inData.getText().toString().trim());
            }
        });

    }

    interface SendMessage {
        void sendData(String message);
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            SM = (SendMessage) getActivity();
        } catch (ClassCastException e) {
            throw new ClassCastException("Error in retrieving data. Please try again");
        }
    }
}

The Custom Interface namely SendMessage is initialised in the onAttach method above. This interface would be implemented in the MainActivity.java that we’ll be seeing shortly. The code for FragmentTwo.java class is given below.

package com.journaldev.passingdatabetweenfragments;


import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class FragmentTwo extends Fragment {

    TextView txtData;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View rootView = inflater.inflate(
                R.layout.fragment_two, container, false);
        return rootView;
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        txtData = (TextView)view.findViewById(R.id.txtData);
    }

    protected void displayReceivedData(String message)
    {
        txtData.setText("Data received: "+message);
    }
}

The displayReceivedData() would be called on the instance of FragmentTwo.java from inside the Custom Interface’s method inside the MainActivity.java as shown below.

package com.journaldev.passingdatabetweenfragments;

import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;

public class MainActivity extends AppCompatActivity implements FragmentOne.SendMessage{

    TabLayout tabLayout;
    ViewPager viewPager;
    ViewPagerAdapter viewPagerAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        viewPager = (ViewPager) findViewById(R.id.viewPager);
        viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(viewPagerAdapter);
        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);
    }

    @Override
    public void sendData(String message) {
        String tag = "android:switcher:" + R.id.viewPager + ":" + 1;
        FragmentTwo f = (FragmentTwo) getSupportFragmentManager().findFragmentByTag(tag);
        f.displayReceivedData(message);
    }
}

The sendData() method in the above code gets triggered as soon as the Button in FragmentOne is pressed. We fetch the FragmentTwo that was already initialised in ViewPagerAdapter using the method findFragmentByTag. The output of the above application in action is given below. android passing data between fragments, android sharing object between fragments example This brings an end to this tutorial. You can download the final Android PassingDataBetweenFragments Project from the link below.

Download Android Passing Data Between Fragments Example Project

Reference: Fragment Communication

If you’ve enjoyed this tutorial and our broader community, consider checking out our DigitalOcean products which can also help you achieve your development goals.

Learn more here


About the authors
Default avatar
Developer and author at DigitalOcean.

Still looking for an answer?

Was this helpful?

hi I want to pass data between fragments using a custom broadcast receiver. how can I do that, please tell me.

- Zubair Hussain

    I am using ViewPager2 and getting this error: Attempt to invoke virtual method ‘void com.pomtech.panda.Fragments.AdminAddNewDetailsFormFragment.displayReceiveMessage(java.lang.String, java.lang.String)’ on a null object reference

    - Ramin Sultanzada

      If you want to access the content value of a component in another Fragment, for instance a TextView, you can access it by finding the View for that Fragment via the container. In the onCreateView method of the Fragment where youwant to access the value, add the two lines at the bottom of my example code. Of course you need to figure out what index the View you are looking for has got in the collection of Views in the container. The View of the first Fragment has got index 0. Two lines of code, that’s all @Override public View onCreateView( LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState ) { View view2 = container.getChildAt(0); TextView tvVehicleId = view2.findViewById(R.id.tvVehicleId);

      - Henrik Stigebrandt

        String tag = “android:switcher:”+R.id.viewPager+“:”+1; Log.e(“”,“Tags is “+tag); FragmentTwo f = (FragmentTwo) getSupportFragmentManager().findFragmentByTag(“android:switcher:”+R.id.viewPager+”:”+1); f.displayReceivedData(message); viewPager.setCurrentItem(1);

        - AKSHAY SHEGAONKAR

          you are awesome guy,i find solution for 2 days but you give me this solution in some minutes thanks a lot

          - “jay”

            It can be done by ViewModel…

            - Rushikesh Patil

              hy.this downlond lik is not valid.

              - Thadi

                Hello, this is the error in my codes java.lang.NullPointerException: Attempt to invoke virtual method ‘void com.example.admin.test2.MainScreen.displayReceivedData(java.lang.String)’ on a null… why would the f be null?

                - Joric

                  Hi I did the codes in this website but I have an error which is “Cannot cast ‘com.example.admin.test2.Expense’ to ‘com.example.admin.test2.MainScreen’” I do not know what this means… I do net have view pager as my fragment transition, I have bottomnav as my fragment transition and I dont know what to do.

                  - Joric

                    Thank you very much! Thank you very much! Thank you very! I cannot express myself how glad I am because your post! I was searching for a solution for more than a week. Previously I was declaring ReceiverFragment receiverFragment = new ReceiverFragment(); in MainActivity. In the function to send the message to fragmentReceiver I was implementing like this: receiverFragment.getMessageFromSender(message); That way I was always getting the NullPointerException for the recyclerView in the ReceiverFragment.java. With your solution the recyclerView is found and everything is working as expected! Thank you very much, once more! link for the Stack Overflow: https://stackoverflow.com/questions/54464482/android-fragment-to-fragment-communication-update-recyclerview-of-the-receiver

                    - Aliton