安卓开发如何实现星级评价

想做一个评价功能 有星级评价 想问的就是 选中五星 怎么让他变成数字 往接口里传
谁有这方面的例子 谢谢了！

1、MainActivity.java

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();
            }
        });
    }
}

2、activity_main.xml

<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>

安卓中有rating bar控件

[html] view plaincopyprint?
<?xml version="1.0" encoding="utf-8"?>

android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<ImageView  
    android:id="@+id/image"  
    android:layout_width="match_parent"  
    android:layout_height="320dp"  
    android:contentDescription="@string/hello"  
    android:src="@drawable/lijiang" />  

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

用OnRatingBarChangeListener来监听评分条的改变。
[java] view plaincopyprint?
public class RatingBarTest extends Activity

{

@Override

public void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

final ImageView image = (ImageView)findViewById(R.id.image);

RatingBar ratingBar = (RatingBar)findViewById(R.id.rating);

    ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener()  
    {  
        //当拖动条的滑块位置发生改变时触发该方法  
        @Override  
        public void onRatingChanged(RatingBar arg0  
            , float rating, boolean fromUser)  
        {  
            //动态改变图片的透明度，其中255是星级评分条的最大值，  
            //5个星星就代表最大值255  
            image.setAlpha((int)(rating * 255 / 5));  
        }  
    });   
}  

}