How to send Data from Activity to fragments in android? PRIMITIVE DATA using Bundle

Useful video : https://youtu.be/R58MvndRAP0

There are 2 ways to do this :

1] Make a Bundle and pass that to the Fragment (If you use this method you can pass data only when the fragment is being created )

2] Create a user defined method inside the fragment so that you can call that method in the mainactivity and send the data.

1] Make a Bundle approach.

first make a bundle in mainactivity and pass it to the fragment object using setArguments().

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    
    //user defined button onclick method
    public void Show(View view) {

        EditText editText = findViewById(R.id.edittext1);
        String message =editText.getText().toString();

        Bundle bundle= new Bundle();
        bundle.putString("keyy",message);

        
        //Creating an object of fragment class
        Datafragment datafragment=new Datafragment();

        //sets the bundle into the fragment class object
        datafragment.setArguments(bundle);

        getSupportFragmentManager().beginTransaction().add(R.id.fragment_container,datafragment).commit();
    }

second...fetch the Bundle  inside the fragment class using getArguments().

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

    View view =inflater.inflate(R.layout.fragment_datafragment, container, false);


    //gets the bundle we passed in the MainActivity
    Bundle bundle = getArguments();
    if (bundle !=null) {
        String message = bundle.getString("keyy");

        TextView textView = view.findViewById(R.id.textview1);
        textView.setText(message);
    }

    return view;
}

2]  Creating a user defined method to get Data. (EASY)

first create a method inside the fragment class so when you create an object in the MainActivity , you can pass the method the data.

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

        View view = inflater.inflate(R.layout.fragment_data, container, false);

            TextView textView =view.findViewById(R.id.textview1);
            textView.setText(message);

        return view;
    }


    public void setData(String m){
        this.message=m;
    }
}

next,fetch the data inside the fragment and assign it a variable 

(Make sure to remove the code for Bundle if you use this method)

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void show(View view) {

        EditText editText =findViewById(R.id.edittext1);
        String message = editText.getText().toString();

        DataFragment dataFragment=new DataFragment();

        
        //user defined method inside the fragment class that will fetch the data
        dataFragment.setData(message);

        getSupportFragmentManager().beginTransaction().add(R.id.fragment_container,dataFragment).commit();

    }
}