Functions and usage of ratingbar

Ratingbar The function and usage of
Star rating bar
The star rating bar and the drag bar have the same parent absSeekBar
RatingBar and Seekbar（ Drag bar ） The biggest difference is ,RatingBar Show progress by stars
android:max=“255” Set progress bar maximum
android:numStars="5" Set the progress bar to a total of several stars
android:progress="255" Set the default maximum value
android:stepSize=“0.5” Set the minimum number of stars to change each time

ratingbar Itself is a special progressbar（ Progress bar ）

public class MainActivity extends Activity {
ImageView iv;
RatingBar rb;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.ratingbar);
iv=(ImageView) findViewById(R.id.image);
rb=(RatingBar) findViewById(R.id.ratingbar);
// Binding event listening

            rb.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {

                    @Override
                    public void onRatingChanged(RatingBar arg0, float arg1, boolean arg2) {
                            // TODO Auto-generated method stub
                            // Dynamically change the transparency of the picture , among 255 Is the maximum value of star rating bar 
                            //5 Stars represent the maximum 255
                            //setImageAlpha Set transparency 
                            iv.setImageAlpha((int) (arg1*255/5));
                    }
            });
    }

}

<?xml version="1.0" encoding="utf-8"?>

<ImageView
    android:id="@+id/image"
    android:layout_width="match_parent"
    android:layout_height="240dp"
    android:src="@drawable/mia8" />
<!--
     Define a star rating bar , Change the transparency of the picture         android:max="255"  Set progress bar maximum 
    android:numStars="5" Set the progress bar to a total of several stars 
    android:progress="255" Set the default maximum value 
    android:stepSize="0.5"  Set the minimum number of stars to change each time 
-->

<RatingBar
    android:id="@+id/ratingbar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:max="255"
    android:numStars="5"
    android:progress="255"
    android:stepSize="0.5" />