官方帮助文档：http://wear.techbrood.com/guide/topics/ui/notifiers/notifications.html

博文推荐：http://blog.csdn.net/x_i_a_o_h_a_i/article/details/32966767

public class MainActivity extends Activity {

	private static final int NOTIFICATION_ID=2003;

	private Button btnNotification;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btnNotification=(Button) findViewById(R.id.btnNotification);

        btnNotification.setOnClickListener(new OnClickListener() {

			@Override

			public void onClick(View v) {

				Builder builder=new NotificationCompat.Builder(MainActivity.this);

				builder.setContentTitle("哇哦，您有一条新消息 ");

				builder.setContentText("放学一起打球吧！");

				builder.setSmallIcon(R.drawable.ic_launcher);

				Notification notification=builder.build();

				notification.flags = Notification.FLAG_AUTO_CANCEL;

				NotificationManager manager=(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

				manager.notify(NOTIFICATION_ID, notification);

			}

		});

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

}

效果：