a Test for notifyDataSetChanged() function on Android

notifyDataSetChanged.java

public class MainActivity extends Activity {

	private Adapter ad;
	private String[] arr = new String[5];

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

		for (int i = 0; i < arr.length; i++) {
			arr[i] = "1";
		}

		ad = new Adapter(this, arr);
		ListView l = (ListView) findViewById(R.id.list);
		l.setAdapter(ad);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		for (int i = 0; i < arr.length; i++) {
			arr[i] = "2";
		}
		ad.notifyDataSetChanged();

		return true;
	}

	private static class Adapter extends BaseAdapter {

		private LayoutInflater mInflater;
		private String[] arr;

		public Adapter(Context c, String[] arr) {
			this.arr = arr;
			mInflater = LayoutInflater.from(c);
		}

		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return arr.length;
		}

		@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) {
			if (null == convertView) {
				convertView = mInflater.inflate(R.layout.a, parent, false);
			}

			TextView t = (TextView) convertView.findViewById(R.id.textView1);
			t.setText(arr[position]);

			return convertView;
		}

	}
}