安卓开发如何实现星级评价

public class MainActivity extends Activity {

    private RatingBar mRatingBar;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRatingBar = (RatingBar) findViewById(R.id.ratingbar);
        mRatingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {

            @Override
            public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {
                Toast.makeText(MainActivity.this, "评价了" + rating + "星", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <RatingBar
        android:id="@+id/ratingbar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numStars="5"
        android:rating="0"
        android:stepSize="1" />

</RelativeLayout>