How to control a fragment from another one

Question

I have written this code ,i have data on data base ,i want to sort listview by age when the button is clicked, the listView should be sorted again by age , now the methods work perfect but i can't resort the list view by age,here is the list fragment code :

import java.util.ArrayList;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class FragmentList extends Fragment {
ListView lst;
DB db;
public static ArrayList<String> LIST;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragmentlist, container,
            false);

    lst = (ListView) rootView.findViewById(R.id.lstViewf);
    db = new DB(getActivity());
    LIST = new ArrayList<String>();

    for (int i = 0; i < db.getAllContacts().size(); i++) {
        LIST.add(db.getAllContacts().get(i).name.toLowerCase());

    }

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
            android.R.layout.simple_list_item_1, LIST);
    lst.setAdapter(adapter);

    return rootView;
}
}

here is Radio fragment that i want to click on one of them to make a change

import java.util.ArrayList;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.Toast; 

public class FragmentRadio extends Fragment {
RadioButton rad1, rad2, rad3;
RadioGroup radioGroup;
DB db;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_radio, container,
            false);
    db = new DB(getActivity());
    rad1 = (RadioButton) rootView.findViewById(R.id.frad1);
    rad2 = (RadioButton) rootView.findViewById(R.id.frad2);
    rad3 = (RadioButton) rootView.findViewById(R.id.frad3);
    radioGroup = (RadioGroup) rootView.findViewById(R.id.radioGroup1);
    radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            if (rad1.getId() == checkedId) {
                Toast.makeText(getActivity(), "!", Toast.LENGTH_SHORT)
                        .show();

                startActivity(new Intent(getActivity(), ListActivity.class));
            }

            else if (rad2.getId() == checkedId) {

                Toast.makeText(getActivity(), "!", Toast.LENGTH_SHORT)
                        .show();

                startActivity(new Intent(getActivity(), ListActivity.class));

                // }

            } else if (rad3.getId() == checkedId) {

            }
        }
    });

    return rootView;
}
}

finally here is the layout that contains the two fragments

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;

public class ListActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list);
    getSupportFragmentManager().beginTransaction()
            .add(R.id.f1, new FragmentList()).commit();
    getSupportFragmentManager().beginTransaction()
            .add(R.id.f2, new FragmentRadio()).commit();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.list, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}


}

XML Files Radio fragment

<RadioGroup
    android:id="@+id/radioGroup1"
    android:layout_width="153dp"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true" >

    <RadioButton
        android:id="@+id/frad1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Sort By Name" />

    <RadioButton
        android:id="@+id/frad2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Sort By age" />

    <RadioButton
        android:id="@+id/frad3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="sort By ID" />
</RadioGroup>

</RelativeLayout>

here is the listfragment xml

<ListView
    android:id="@+id/lstViewf"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >
</ListView>

</LinearLayout>

http://stackoverflow.com/questions/13700798/basic-communication-between-two-fragments — nobalG, Jul 17 '14 at 11:59

Omar Albelbaisy · Accepted Answer · 2014-07-17T13:54:27.603

You can set a TAG for the FragmentList as follow

getSupportFragmentManager().beginTransaction().add(R.id.f1, new FragmentList(),"YOUR_TAG").commit();

Then in FragmentRadio class you can get a reference to FragmentList as follow

FragmentList fragmentList = (FragmentList) getActivity().getSupportFragmentManager().findFragmentByTag("YOUR_TAG");

After that you can create sortList() method in your FragmentList class and call it directly from the other fragment fragmentList.sortList();

But i don't recommend the direct communication between fragments, it's better to create a callback interface and use the activity as intermediate between the two fragments.

Check this to learn how to implement the callback interface and use it to communicate betweem fragments http://developer.android.com/guide/components/fragments.html#EventCallbacks

score 0 · Answer 2 · answered Jul 17 '14 at 12:53

0

You can create an interface between your fragments and your activity. The fragment you want to be your controller will send callbacks to your fragment using the activity.

answered Jul 17 '14 at 12:53

AlexBalo

1,258
1
11
16

can you please provide me an example ? i want to control list view ,should i put an inteface there ? or at radio frament which will control the second activity – Basil Battikhi Jul 17 '14 at 13:38
Can you please briefly describe me your scenario? – AlexBalo Jul 17 '14 at 13:48

How to control a fragment from another one

2 Answers2