学步园

public class MainActivity extends Activity {
	private NotificationManager manager = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_BACK) {
			Notification notification = new Notification(R.drawable.ic_launcher, "MyApp", System.currentTimeMillis());
			Intent intent = new Intent(MainActivity.this, MainActivity.class);
			PendingIntent pendingIntent = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);
			
			notification.flags |= Notification.FLAG_AUTO_CANCEL;
			notification.flags |= Notification.FLAG_NO_CLEAR;
			notification.setLatestEventInfo(MainActivity.this, "提示文字", "", pendingIntent);
			manager.notify(1, notification);
		}
		return super.onKeyDown(keyCode, event);
	}
}

注意在onResume和onPause里对后台的服务进行处理

Notification的详细用法，参见http://blog.csdn.net/feng88724/article/details/6259071