Complete list with files for the CustomAdapter post of my blog.

CustomAdapter.java

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import java.util.List;


public class CustomAdapter extends ArrayAdapter<String> {

    protected Context mContext;
	
	private LayoutInflater mInflater;

    public CustomAdapter(Context context, List<String> objects) {
        super(context, 0, objects);
        this.mContext = context;
		mInflater = LayoutInflater.from(context);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        //If convertView is null, we inflate our Layout in convertView.
        if (convertView == null) {

            convertView = mInflater.inflate(R.layout.item_layout, parent, false);

            //We instantiate our ViewHolder object, in order to use it below.
            holder = new ViewHolder();

            //Let's say that our custom layout file contains only one TextView.
            //So we use the ViewHolder pattern to instantiate it.
            holder.mTextView = (TextView) convertView.findViewById(R.id.textView);

            convertView.setTag(holder);

        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        //Because we extend ArrayAdapter, we can use the position and retrieve
        //the current object using the getItem(int i) method.
        String item = getItem(position);

        //We only execute the following, if our item is not null.
		if (item != null){

			holder.mTextView.setText(item);
		}

        return convertView;
    }

    private static class ViewHolder {
		TextView mTextView;
    }

    public Context getContext() {
        return mContext;
    }

}

CustomListActivity.java

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.view.View;
import java.util.ArrayList;
import android.widget.TextView;
import android.widget.AdapterView;



public class CustomListActivity extends Activity {

    private ListView mListView;

	private CustomAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_custom_list);

        //ListView instantiation
        mListView = (ListView) findViewById(android.R.id.list);
		
		ArrayList<String> lists = new ArrayList<String>();
		
        //Filling an ArrayList with our objects
		lists.add("a");
		lists.add("b");
		lists.add("c");
		lists.add("d");
		
        //Initializing our CustomAdapter and passing the context and our data.
		mAdapter = new CustomAdapter(this,lists);
    
        //Setting the adapter to our ListView
		if (mListView != null){
			mListView.setAdapter(mAdapter);			
		}
        
    }

}

item_layout.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Medium Text"
        android:id="@+id/textView"
        android:layout_gravity="center_horizontal" />
    
</LinearLayout>