❮ Android Environment Setup Android Eclipse ❯

Android List Fragment

The basic implementation of a list fragment is used to create a list of items within a fragment.

Example

This example explains how to create a list fragment based on ArrayAdapter. Let's start with the following steps:

Step	Description
1	Create an Android application using Android Studio, named List Fragment, with package name cn.uprogrammer.listfragment
2	Modify the string file, add new string constants in res/values/string.xml
3	Create a layout file named list_fragment.xml under res/layout to define the list fragment, and add a fragment tag in activity_main.xml
4	Create MyListFragment.java file, which includes onCreateView(), onActivityCreated(), and OnItemClickListener() methods.
5	Start the Android emulator to run the application and verify the changes made.

Before starting coding, initialize string constants in the string.xml file under the res/values directory.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">listfragment</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string name="title_activity_main">List Fragment Demo</string>
    <string name="imgdesc">imgdesc</string>

    &lt;string-array name="Planets">
        <item>Sun</item>
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>
        <item>Mars</item>
        <item>Jupiter</item>
        <item>Saturn</item>
        <item>Uranus</item>
        <item>Neptune</item>
    </string-array>
</resources>

Below is the content of the res/layout/activity_main.xml file, which includes a LinearLayout and a fragment tag.

<?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="match_parent"
    android:orientation="vertical" >

    <fragment
        android:id="@+id/fragment1"
        android:name="cn.uprogrammer.listfragment.MyListFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

Below is the content of the res/layout/list_fragment.xml file, which includes a LinearLayout, ListView, and TextView.

<?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="match_parent"
    android:orientation="vertical" >

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

    <TextView
        android:id="@android:id/empty"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </TextView>
</LinearLayout>

Below is the content of the src/cn.uprogrammer.listfragment/MyListFragment.java file. Before starting coding, follow these steps:

Create the MyListFragment class, inheriting from ListFragment.
In the onCreateView() method, use the list_fragment xml layout defined above to inflate the view.
In the onActivityCreated() method, create an ArrayAdapter using the string array R.array.planet resource defined in string.xml, set the adapter to the ListView, and set the item click listener.

In the OnItemClickListener() method, display the position of the clicked item as a toast message.

package cn.uprogrammer.listfragment;

import android.app.ListFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Toast;

public class MyListFragment extends ListFragment implements AdapterView.OnItemClickListener {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.list_fragment, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        ArrayAdapter adapter = ArrayAdapter.createFromResource(getActivity(), R.array.Planets, android.R.layout.simple_list_item_1);
        setListAdapter(adapter);
        getListView().setOnItemClickListener(this);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Toast.makeText(getActivity(), "Item: " + position, Toast.LENGTH_SHORT).show();
    }
}

Below is the content of MainActivity.java:

package cn.uprogrammer.listfragment;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

Below is the content of the AndroidManifest.xml file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cn.uprogrammer.listfragment">

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>
</manifest>

Let's run the modified List Fragment application. I assume you have already created an AVD when setting up the environment. Open the activity file in your project and click on the run icon in the toolbar.

❮ Android Environment Setup Android Eclipse ❯