Interactions between Fragments
Description
We can make fragments to communicate with one another and exchange data.
Example
The following code shows how one fragment can access the views contained within another fragment.
In the res/layout folder, add a new file and name it fragment1.xml.
Populate it with the following:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout// w w w . ja v a 2 s .com
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#00FF00" >
<TextView
android:id="@+id/lblFragment1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="This is fragment #1"
android:textColor="#000000"
android:textSize="25sp" />
</LinearLayout>
Also in the res/layout folder, add another new file and name it fragment2.xml.
Populate it as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout// www .ja v a 2 s .c o m
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFE00" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="This is fragment #2"
android:textColor="#000000"
android:textSize="25sp" />
<Button
android:id="@+id/btnGetText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Get text in Fragment #1"
android:textColor="#000000"
android:onClick="onClick" />
</LinearLayout>
In activity_main.xml, add the following code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
// w w w . ja v a 2 s .c om
<fragment
android:name="com.java2s.myapplication3.app.Fragment1"
android:id="@+id/fragment1"
android:layout_weight="1"
android:layout_width="0px"
android:layout_height="match_parent" />
<fragment
android:name="com.java2s.myapplication3.app.Fragment2"
android:id="@+id/fragment2"
android:layout_weight="1"
android:layout_width="0px"
android:layout_height="match_parent" />
</LinearLayout>
Modify the MainActivity.java file as follows:
public class MainActivity extends Activity {
@Override//w ww . j av a2 s .c o m
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
Under the com.java2s.Fragments package name, add two
Java class files and name them Fragment1.java and Fragment2.java
Add the following code to Fragment1.java:
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
//from w ww . j av a 2 s . c o m
public class Fragment1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
//Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment1, container, false);
}
}
Add the following code to Fragment2.java:
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
/* w w w. j a v a 2s . c o m*/
public class Fragment2 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(
R.layout.fragment2, container, false);
}
@Override
public void onStart() {
super.onStart();
Button btnGetText = (Button)
getActivity().findViewById(R.id.btnGetText);
btnGetText.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
TextView lbl = (TextView)
getActivity().findViewById(R.id.lblFragment1);
Toast.makeText (getActivity(), lbl.getText(),
Toast.LENGTH_SHORT).show();
}
});
}
}
Note
Debug the application on the Android emulator.
In the second fragment on the right, click the button. You should see the Toast class displaying the text "This is fragment #1".