public class MainActivity extends Activity {
  RatingBar ratingBar ;RatingBar ratingBar02 ;
  TextView textView ;
  ImageView imageView ;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ratingBar = (RatingBar) findViewById(R.id.rating);
    ratingBar02 = (RatingBar) findViewById(R.id.rating02);
    textView = (TextView) findViewById(R.id.textview);
    imageView = (ImageView) findViewById(R.id.image);
    ratingBar.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
      @Override
      public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {
        textView.setText(String.valueOf((int) (rating)));
      }
    });
    ratingBar02.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
      @Override
      public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {
        imageView.setAlpha((int)(rating*255/5));
      }
    });
  }
}

<?xml version="1.0" encoding="utf-8" ?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical">
  <TextView
    android:id="@+id/textview"
    android:layout_width="match_parent"
    android:layout_height="75dp"
    android:gravity="center_horizontal"
    android:textSize="50dp"/>
  <!--android:progressDrawable自定義樣式-->
  <RatingBar
    android:id="@+id/rating"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:numStars="5"
    android:max="255"
    android:progress="255"
    android:stepSize="0.5"/>
  <ImageView
    android:id="@+id/image"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:src="@drawable/huangjindiao"/>
  <RatingBar
    android:id="@+id/rating02"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:numStars="5"
    android:progressDrawable="@drawable/my_bar"
    android:stepSize="0.5"/>
</LinearLayout>