RatingBar

 1 package gdp.ratingbartest;
 2 
 3 import android.annotation.SuppressLint;
 4 import android.app.Activity;
 5 import android.os.Bundle;
 6 import android.view.Menu;
 7 import android.widget.ImageView;
 8 import android.widget.RatingBar;
 9 import android.widget.RatingBar.OnRatingBarChangeListener;
10 
11 public class MainActivity extends Activity {
12     private ImageView imageView;
13     private RatingBar ratingBar;
14     @Override
15     protected void onCreate(Bundle savedInstanceState) {
16         super.onCreate(savedInstanceState);
17         setContentView(R.layout.main);
18         //获得控件对象
19         imageView = (ImageView)findViewById(R.id.imageView);
20         ratingBar = (RatingBar)findViewById(R.id.ratingBar);
21         //为RatingBar绑定监听器
22         ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
23             
24             @SuppressLint("NewApi")
25             @Override
26             public void onRatingChanged(RatingBar arg0, float arg1, boolean arg2) {
27                 // TODO Auto-generated method stub
28                 //动态改变图片透明度
29                 int ratingInt = (int)(255 / 5 * arg1);
30                 imageView.setImageAlpha(ratingInt);
31             }
32         });
33     }
34 
35     @Override
36     public boolean onCreateOptionsMenu(Menu menu) {
37         // Inflate the menu; this adds items to the action bar if it is present.
38         getMenuInflater().inflate(R.menu.main, menu);
39         return true;
40     }
41 
42 }

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:layout_width="fill_parent"
 3     android:layout_height="fill_parent"
 4     android:orientation="vertical" >
 5     <ImageView
 6         android:id="@+id/imageView"
 7         android:layout_width="wrap_content"
 8         android:layout_height="wrap_content"
 9         android:src="@drawable/home"
10         android:layout_gravity="center_horizontal"
11         />
12 
13     <RatingBar
14         android:id="@+id/ratingBar"
15         android:layout_width="wrap_content"
16         android:layout_height="wrap_content"
17         android:numStars="5"
18         android:max="255"
19         android:progress="255"
20         android:stepSize="0.5"        
21         />
22 </LinearLayout>