ListView Android

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To include a group of items to be displayed in a scrollable list, the Android ListView is used. It is a view. By importing the android.widget.ListView class, the ListView is implemented. It does not use other scroll views as it is a default scrollable. The Adapter classes are used by the ListView to add the content from the data source to the ListView. The data source can be a string array, array, database, etc. The data between the AdapterViews and other Views like ListView, ScrollView, etc are bridged by the Adapter.

Example of ListView:

activity_main.xml:

In the activity_main.xml file, we will drag and drop the ListView component from the palette.

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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">
 
   <ListView
       android:id="@+id/listView"
       android:layout_width="match_parent"
       android:layout_height="fill_parent"
       tools:ignore="MissingConstraints" />
</android.support.constraint.ConstraintLayout>

mylist.xml:

The view components displayed in the ListView are added in the mylist.xml file which is an additional file created in the layout folder.

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
   android:id="@+id/textView"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Medium Text"
   android:textStyle="bold"
   android:textAppearance="?android:attr/textAppearanceMedium"
   android:layout_marginLeft="10dp"
   android:layout_marginTop="5dp"
   android:padding="2dp"
   android:textColor="#4d4d4d"
   />

strings.xml:

<resources>
   <string name="app_name">radioapp</string>
   <string-array name="alphabets">
       <item>A</item>
       <item>B</item>
       <item>C</item>
       <item>D</item>
       <item>E</item>
       <item>F</item>
       <item>G</item>
       <item>H</item>
       <item>I</item>
       <item>J</item>
       <item>K</item>
       <item>L</item>
       <item>M</item>
       <item>N</item>
       <item>O</item>
       <item>P</item>
       <item>Q</item>
       <item>R</item>
       <item>S</item>
       <item>T</item>
       <item>U</item>
       <item>V</item>
       <item>W</item>
       <item>X</item>
       <item>Y</item>
       <item>Z</item>
   </string-array>
</resources>

Activity class:(File: MainActivity.java)

The setAdapter() method of the ListView is used in the MainActivity.java file to add the adapter to the Listview.

package com.example.radioapp;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
 
public class MainActivity extends AppCompatActivity {
   ListView listView;
   TextView textView;
   String[] listItem;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
 
       listView=(ListView)findViewById(R.id.listView);
       textView=(TextView)findViewById(R.id.textView);
       listItem = getResources().getStringArray(R.array.alphabets);
       final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
               android.R.layout.simple_list_item_1, android.R.id.text1, listItem);
       listView.setAdapter(adapter);
 
       listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
           @Override
           public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
               // TODO Auto-generated method stub
               String value=adapter.getItem(position);
               Toast.makeText(getApplicationContext(),value,Toast.LENGTH_SHORT).show();
 
           }
       });
   }
}

Output 1:

Output 2: