Saturday, October 5, 2019

Android ListView with Examples

In android, ListView is a ViewGroup which is used to display the list of scrollable of items in multiple rows and the list items are automatically inserted to the list using an adapter.

Generally, the adapter pulls data from a sources such as an array or database and converts each item into a result view and that’s placed into the list.

Following is the pictorial representation of listview in android applications.

Android ListView Example Diagram

Android Adapter

In android, Adapter will act as an intermediate between the data sources and adapter views such as ListViewGridview to fill the data into adapter views. The adapter will hold the data and iterates through an items in data set and generate the views for each item in the list.

Generally, in android we have a different types of adapters available to fetch the data from different data sources to fill the data into adapter views, those are

AdapterDescription
ArrayAdapterIt will expects an Array or List as input.
CurosrAdapterIt will accepts an instance of cursor as an input.
SimpleAdapterIt will accepts a static data defined in the resources.
BaseAdapterIt is a generic implementation for all three adapter types and it can be used for ListViewGridview or Spinners based on our requirements

Android ListView Example

Following is the example of creating a ListView using arrayadapter in android application.

Create a new android application using android studio and give names as ListView. In case if you are not aware of creating an app in android studio check this article Android Hello World App.

Now open an activity_main.xml file from \res\layout path and write the code like as shown below

activity_main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    
xmlns:tools="http://schemas.android.com/tools"
    
android:layout_width="match_parent"
    
android:layout_height="match_parent"
    
android:orientation="vertical">
    <
ListView
        
android:id="@+id/userlist"
        
android:layout_width="match_parent"
        
android:layout_height="wrap_content" >
    </
ListView>
</
LinearLayout>
Once we are done with creation of layout, now we will bind data to our ListView using ArrayAdapter, for that open main activity file MainActivity.java from \java\com.tutlane.listview path and write the code like as shown below.

MainActivity.java

package com.tutlane.listview;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.widget.ArrayAdapter;import android.widget.ListView;
public class MainActivity extends AppCompatActivity {
    
private ListView mListView;
    
private ArrayAdapter aAdapter;
    
private String[] users = { "Suresh Dasari""Rohini Alavala""Trishika Dasari""Praveen Alavala""Madav Sai""Hamsika Yemineni"};
    
@Override
    
protected void onCreate(Bundle savedInstanceState) {
        
super.onCreate(savedInstanceState);
        setContentView(R.layout.
activity_main);
        
mListView = (ListView) findViewById(R.id.userlist);
        
aAdapter new ArrayAdapter(this, android.R.layout.simple_list_item_1users);
        
mListView.setAdapter(aAdapter);
    }
}
If you observe above code, we are binding static array (users) details to ListView using ArrayAdapter and calling our layout using setContentView method in the form of R.layout.layout_file_name. Here our xml file name is activity_main.xml so we used file name activity_main.

Generally, during the launch of our activity, onCreate() callback method will be called by android framework to get the required layout for an activity.

Output of Android ListView Example

When we run above example using android virtual device (AVD) we will get a result like as shown below.

Android ListView Example Result

This is how we can bind data to ListView using ArrayAdapter in android applications based on our requirements.

Android ListView with Custom Adapter Example

In previous example, we learned simple way to bind data to ListView using ArrayAdapter in android application. Now we will see how to create our own custom adapter and bind data to ListView with example.

For this, we need to create our own custom adapter class by extending with BaseAdapter class and create a class which will contain a parameters for list row items.

Now create a new android application using android studio and give names as ListView. In case if you are not aware of creating an app in android studio check this article Android Hello World App.

Open an activity_main.xml file from \res\layout path and write the code like as shown below

activity_main.xml

<?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="vertical" >
    <
ListView
        
android:id="@+id/user_list"
        
android:layout_width="fill_parent"
        
android:layout_height="wrap_content"
        
android:dividerHeight="1dp" />
</
LinearLayout>
Now we need to create a layout for listview row items, for that right click on layouts folder à select New à Layout resource file à Give name as list_row.xml and click OK. Now open newly created file (list_row.xml) and write the code like as shown below

list_row.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    
android:layout_width="fill_parent"
    
android:layout_height="wrap_content"
    
android:orientation="horizontal"
    
android:padding="5dip" >
    <
TextView
        
android:id="@+id/name"
        
android:layout_width="wrap_content"
        
android:layout_height="wrap_content"
        
android:textStyle="bold"
        
android:textSize="17dp" />
    <
TextView
        
android:id="@+id/designation"
        
android:layout_width="wrap_content"
        
android:layout_height="wrap_content"
        
android:layout_below="@id/name"
        
android:layout_marginTop="7dp"
        
android:textColor="#343434"
        
android:textSize="14dp" />
    <
TextView
        
android:id="@+id/location"
        
android:layout_width="wrap_content"
        
android:layout_height="wrap_content"
        
android:layout_alignBaseline="@+id/designation"
        
android:layout_alignBottom="@+id/designation"
        
android:layout_alignParentRight="true"
        
android:textColor="#343434"
        
android:textSize="14dp" />
</
RelativeLayout>
Now we need to create a custom class (ListItem.java) to represent each row in the list, for that right click on java folder à select New à Java Class à Give name as ListItem.java and click OK. Open ListItem.java file and write the code like as shown below

ListItem.java

package com.tutlane.listview;/**
 * Created by tutlane on 23-08-2017.
 */
public class ListItem {
    
private String name;
    
private String designation;
    
private String location;
    
public String getName() {
        
return name;
    }
    
public void setName(String name) {
        
this.name = name;
    }
    
public String getDesignation() {
        
return designation;
    }
    
public void setDesignation(String designation) {
        
this.designation = designation;
    }
    
public String getLocation() {
        
return location;
    }
    
public void setLocation(String location) {
        
this.location = location;
    }
}
Now we need to create a custom adapter (CustomListAdapter.java) and extend it by using BaseAdapter. In case if we are extending our class by using BaseAdapter, we need to override following methods from BaseAdapter class.

MethodDescription
getCount()It will return total number of rows count in listview
getItem()It is used to specify the object data of each row
getItemId()It return the id of each row item
getView()It is used to return a view instance that represents a single row in ListView item.
To create custom adapter right click on java folder à select New à Java Class à Give name as CustomListAdapter.java and click OK.

Open CustomListAdapter.java file and write the code like as shown below

CustomListAdapter.java

package com.tutlane.listview;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.TextView;
import java.util.ArrayList;/**
 * Created by tutlane on 23-08-2017.
 */
public class CustomListAdapter extends BaseAdapter {
    
private ArrayList<ListItem> listData;
    
private LayoutInflater layoutInflater;
    
public CustomListAdapter(Context aContext, ArrayList<ListItem> listData) {
        
this.listData = listData;
        
layoutInflater = LayoutInflater.from(aContext);
    }
    
@Override
    
public int getCount() {
        
return listData.size();
    }
    
@Override
    
public Object getItem(int position) {
        
return listData.get(position);
    }
    
@Override
    
public long getItemId(int position) {
        
return position;
    }
    
public View getView(int position, View v, ViewGroup vg) {
        ViewHolder holder;
        
if (v == null) {
            v = 
layoutInflater.inflate(R.layout.list_rownull);
            holder = 
new ViewHolder();
            holder.
uName = (TextView) v.findViewById(R.id.name);
            holder.
uDesignation = (TextView) v.findViewById(R.id.designation);
            holder.
uLocation = (TextView) v.findViewById(R.id.location);
            v.setTag(holder);
        } 
else {
            holder = (ViewHolder) v.getTag();
        }
        holder.
uName.setText(listData.get(position).getName());
        holder.
uDesignation.setText(listData.get(position).getDesignation());
        holder.
uLocation.setText(listData.get(position).getLocation());
        
return v;
    }
    
static class ViewHolder {
        TextView 
uName;
        TextView 
uDesignation;
        TextView 
uLocation;
    }
}
If you observe above class we are extending our custom adapter by using BaseAdapter and we override all BaseAdapter methods in our custom adapter.

Now we need to combine all the custom classes in main activity file (MainActivity.java) to bind the data to our listview.

Open main activity file (MainActivity.java) and write the code like as shown below.

MainActivity.java

package com.tutlane.listview;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.ListView;import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
    
@Override
    
protected void onCreate(Bundle savedInstanceState) {
        
super.onCreate(savedInstanceState);
        setContentView(R.layout.
activity_main);
        ArrayList userList = getListData();
        
final ListView lv = (ListView) findViewById(R.id.user_list);
        lv.setAdapter(
new CustomListAdapter(this, userList));
        lv.setOnItemClickListener(
new AdapterView.OnItemClickListener() {
            
@Override
            
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
                ListItem user = (ListItem) 
lv.getItemAtPosition(position);
                Toast.makeText(MainActivity.
this"Selected :" " " + user.getName()+", "+ user.getLocation(), Toast.LENGTH_SHORT).show();
            }
        });
    }
    
private ArrayList getListData() {
        ArrayList<ListItem> results = 
new ArrayList<>();
        ListItem user1 = 
new ListItem();
        user1.setName(
"Suresh Dasari");
        user1.setDesignation(
"Team Leader");
        user1.setLocation(
"Hyderabad");
        results.add(user1);
        ListItem user2 = 
new ListItem();
        user2.setName(
"Rohini Alavala");
        user2.setDesignation(
"Agricultural Officer");
        user2.setLocation(
"Guntur");
        results.add(user2);
        ListItem user3 = 
new ListItem();
        user3.setName(
"Trishika Dasari");
        user3.setDesignation(
"Charted Accountant");
        user3.setLocation(
"Guntur");
        results.add(user3);
        
return results;
    }
}
If you observe above code we are building and binding data to ListView using our custom adapter and calling our layout using setContentView method in the form of R.layout.layout_file_name. Here our xml file name is activity_main.xml so we used file name activity_main.

Generally, during the launch of our activityonCreate() callback method will be called by android framework to get the required layout for an activity.

Output of Android Custom ListView Example

When we run above example using android virtual device (AVD) we will get a result like as shown below.

Android ListView with Custom Adapter Example 
 This is how we can bind data to ListView using custom adapter in android applications based on our requirements. 

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