How to implement android ListView using custom adapter | Android | Java

In this article, I will demonstrate how we can implement an android listview with custom apdater.

Step 1. Open Android Studio, click on a new project and select an empty layout then enter your project name then hit finish.

Step 2. Now take list view in your main activity layout as bellow

<ListView
    android:layout_below="@+id/tv_title"
    android:id="@+id/lv_items"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
</ListView>

Or simply replace with your activity.xml file with below code

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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">
    <TextView
        android:id="@+id/tv_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Android List View"
        android:textAlignment="center"
        android:layout_marginBottom="10dp"/>
    <ListView
        android:layout_below="@+id/tv_title"
        android:id="@+id/lv_items"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ListView>
</RelativeLayout>

Step 3. Now create a model class to add multi-dimension array list as below and name it model.java .

model.java

package com.sahebul.simplelistview;

/**
 * Created by Sahebul on 25/5/19.
 */
public class model {
    private String ItemName;
    private String ItemQty;

    public String getItemName() {
        return ItemName;
    }

    public void setItemName(String itemName) {
        ItemName = itemName;
    }

    public String getItemQty() {
        return ItemQty;
    }

    public void setItemQty(String itemQty) {
        ItemQty = itemQty;
    }

    public model(String itemName, String itemQty) {
        ItemName = itemName;
        ItemQty = itemQty;
    }

    public model() {
    }
}

Step 4. Now create your adapter class as shown below

Adapter.java

package com.sahebul.simplelistview;

import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.List;

/**
 * Created by Sahebul on 25/5/19.
 */
public class Adapter extends BaseAdapter {
    List<model> data;
    Activity activity;
    private LayoutInflater inflater;

    public Adapter(Activity activity, List<model> data) {
        inflater = activity.getLayoutInflater();
        this.activity = activity;
        this.data = data;
    }

    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final Adapter.MyViewHolder mViewHolder;
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.single_item, parent, false);
            mViewHolder = new Adapter.MyViewHolder(convertView);
            convertView.setTag(mViewHolder);
        } else {
            mViewHolder = (Adapter.MyViewHolder) convertView.getTag();
        }
        mViewHolder.tv_name.setText(data.get(position).getItemName());
        mViewHolder.tv_qty.setText(data.get(position).getItemQty());
        return convertView;
    }

    public class MyViewHolder {
        private TextView tv_name, tv_qty;

        public MyViewHolder(View item) {
            tv_name = (TextView) item.findViewById(R.id.tv_name);
            tv_qty = (TextView) item.findViewById(R.id.tv_qty);
        }
    }
}

Step 5. Now open your MainActivity.java file and initialize an array list of an item which we will show on list view as below.

ArrayList<model> list=new ArrayList<>();

step 6. Create load_items() function in MainActivity.java to load the array lits as below

public void load_items(){
    for (int i=0;i<20;i++){
        Integer num=i+1;
        list.add(new model("Item "+num,num+""));
    }

}

Now just call the load_items() function on your onCreate() method.

Step 6. Now set your adapter as below in onCreate method

Adapter adapter = new Adapter(this,  list );
itemListView.setAdapter(adapter);

MainActivity.java

package com.sahebul.simplelistview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;

import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {

    ArrayList<model> list=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView itemListView=findViewById(R.id.lv_items);
        //load the item list to display
        load_items();
        //set a string adapter
        Adapter adapter = new Adapter(this,  list );
        itemListView.setAdapter(adapter);

    }
    public void load_items(){
        for (int i=0;i<20;i++){
            Integer num=i+1;
            list.add(new model("Item "+num,num+""));
        }

    }
}