How to Send Data From Activity to Fragment in Android?
Prerequisites:
In Android, a fragment is a portion of the user interface that can be used again and again. Fragment manages its own layout and has its own life cycle. Since fragment is a small portion of the bigger user interface, it can only be initialized inside an activity or another fragment. So if we wish to display any type of resources, such as a string, or an image inside the fragment, we will need to declare them in the activity and then pass it to the fragment. So in this article, we will show you how you can pass data from an Activity to the Fragment.
Step by Step Implementation
Step 1: Create a New Project in Android Studio
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.
Step 2: Create a custom fragment layout (my_custom_fragment.xml) in the layout folder
We shall pass a string to the fragment. To display this string, we implemented a TextView.
XML
<? xml version = "1.0" encoding = "utf-8" ?> < LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android" android:layout_width = "match_parent" android:layout_height = "wrap_content" android:orientation = "vertical" > <!-- TextVIew to display the passed text --> < TextView android:id = "@+id/fragmentTextView" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:layout_gravity = "center" android:textColor = "@color/white" android:textSize = "50sp" android:background = "#0f9d58" /> </ LinearLayout > |
Step 3: Add EditText, Button, and Frame in the layout file (activity_main.xml)
Refer to the comments inside the code for better understanding.
XML
<? 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" xmlns:tools = "http://schemas.android.com/tools" android:layout_width = "match_parent" android:layout_height = "match_parent" tools:context = ".MainActivity" > <!-- We will type text in this EditText --> < EditText android:id = "@+id/editText" android:layout_width = "match_parent" android:layout_height = "50sp" /> <!-- Click this button to pass text in EditText to the Fragment --> < Button android:id = "@+id/button" android:layout_below = "@+id/editText" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:layout_centerHorizontal = "true" android:text = "Pass" /> <!-- Text will be displayed in a TextView in this Fragment --> < FrameLayout android:id = "@+id/frameLayout" android:layout_below = "@+id/button" android:layout_width = "match_parent" android:layout_height = "match_parent" /> </ RelativeLayout > |
Step 4: Create a class for the custom fragment (MyCustomFragment.kt)
This is a custom fragment class to inflate the custom layout in the frame layout present in the main activity.
Kotlin
import android.os.Bundle import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import android.widget.TextView import androidx.fragment.app.Fragment class MyCustomFragment: Fragment() { // Declaring TextView from the custom fragment layout private lateinit var myTextView: TextView // Override function when the view is being created override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View { // Inflates the custom fragment layout val view: View = inflater.inflate(R.layout.my_custom_fragment, container, false ) // Finds the TextView in the custom fragment myTextView = view.findViewById<View>(R.id.fragmentTextView) as TextView // Gets the data from the passed bundle val bundle = arguments val message = bundle!!.getString( "mText" ) // Sets the derived data (type String) in the TextView myTextView.text = message return view } } |
Java
import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import androidx.fragment.app.Fragment; public class MyCustomFragment extends Fragment { // Declaring TextView from the custom fragment layout private TextView myTextView; // Override function when the view is being created @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflates the custom fragment layout View view = inflater.inflate( R.layout.my_custom_fragment, container, false ); // Finds the TextView in the custom fragment myTextView = (TextView)view.findViewById( R.id.fragmentTextView); // Gets the data from the passed bundle Bundle bundle = getArguments(); String message = bundle.getString( "mText" ); // Sets the derived data (type String) in the // TextView myTextView.setText(message); return view; } } |
Step 5: Initialize MyCustomFragment class and pass the values from the EditText (MainActivity.kt)
In this program, the EditText value (input string) is fetched on a button click. The custom fragment class is initialized and the input string is passed to get desired results. Please refer to the comments inside the code below for a better understanding.
Kotlin
import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import android.widget.Button import android.widget.EditText class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super .onCreate(savedInstanceState) setContentView(R.layout.activity_main) // Declaring and initializing the EditText and Button from the layout val mEditText = findViewById<EditText>(R.id.editText) val mButton = findViewById<Button>(R.id.button) // Declaring fragment manager from making data // transactions using the custom fragment val mFragmentManager = supportFragmentManager val mFragmentTransaction = mFragmentManager.beginTransaction() val mFragment = MyCustomFragment() // On button click, a bundle is initialized and the // text from the EditText is passed in the custom // fragment using this bundle mButton.setOnClickListener { val mBundle = Bundle() mBundle.putString( "mText" ,mEditText.text.toString()) mFragment.arguments = mBundle mFragmentTransaction.add(R.id.frameLayout, mFragment).commit() } } } |
Java
import android.os.Bundle; import android.widget.Button; import android.widget.EditText; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Declaring and initializing the EditText and // Button from the layout final EditText mEditText = findViewById(R.id.editText); final Button mButton = findViewById(R.id.button); // Declaring fragment manager from making data // transactions using the custom fragment final androidx.fragment.app .FragmentManager mFragmentManager = getSupportFragmentManager(); final androidx.fragment.app .FragmentTransaction mFragmentTransaction = mFragmentManager.beginTransaction(); final MyCustomFragment mFragment = new MyCustomFragment(); // On button click, a bundle is initialized and the // text from the EditText is passed in the custom // fragment using this bundle mButton.setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { Bundle mBundle = new Bundle(); mBundle.putString( "mText" , mEditText.getText().toString()); mFragment.setArguments(mBundle); mFragmentTransaction .add(R.id.frameLayout, mFragment) .commit(); } }); } } |
Output:
We can see that when the text is typed in the EditText and the button is clicked, the same text is displayed in our custom fragment.
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