1.布局
代码语言：javascript复制 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
2 xmlns:tools="http://schemas.android.com/tools"
3 android:layout_width="match_parent"
4 android:layout_height="match_parent"
5 android:orientation="vertical"
6 tools:context=".AndroidSeekBarActivity" >
7
8 <ImageView
9 android:id="@ id/img"
10 android:layout_width="match_parent"
11 android:layout_height="240px"
12 android:src="@drawable/mm" />
13
14 <SeekBar
15 android:id="@ id/sekbar"
16 android:layout_width="match_parent"
17 android:layout_height="wrap_content"
18 android:max="255"
19 android:progress="255"
20 android:thumb="@drawable/sj" />
21
22 <RatingBar
23 android:id="@ id/ratbar"
24 android:layout_width="match_parent"
25 android:layout_height="wrap_content"
26 android:max="255"
27 android:numStars="5"
28 android:progress="255"
29 android:stepSize="0.5" />
30
31 </LinearLayout>2.逻辑控制
代码语言：javascript复制 1 package com.example.androidseekbar;
2
3 import android.os.Bundle;
4 import android.app.Activity;
5 import android.view.Menu;
6 import android.widget.ImageView;
7 import android.widget.RatingBar;
8 import android.widget.RatingBar.OnRatingBarChangeListener;
9 import android.widget.SeekBar;
10 import android.widget.SeekBar.OnSeekBarChangeListener;
11
12 public class AndroidSeekBarActivity extends Activity {
13
14 @Override
15 protected void onCreate(Bundle savedInstanceState) {
16 super.onCreate(savedInstanceState);
17 setContentView(R.layout.activity_android_seek_bar);
18
19 final ImageView img = (ImageView) this.findViewById(R.id.img);
20 SeekBar sekbar = (SeekBar) this.findViewById(R.id.sekbar);
21 sekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
22
23 @Override
24 public void onStopTrackingTouch(SeekBar seekBar) {
25 // TODO Auto-generated method stub
26
27 }
28
29 @Override
30 public void onStartTrackingTouch(SeekBar seekBar) {
31 // TODO Auto-generated method stub
32
33 }
34
35 @Override
36 public void onProgressChanged(SeekBar seekBar, int progress,
37 boolean fromUser) {
38 // 拖动时触发
39 img.setAlpha(progress);
40 }
41 });
42
43 RatingBar ratbar=(RatingBar)this.findViewById(R.id.ratbar);
44 ratbar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
45
46 @Override
47 public void onRatingChanged(RatingBar arg0, float rating, boolean arg2) {
48 //动态改变图片透明度
49 img.setAlpha((int)(rating*255/5));
50 }
51 });
52 }
53
54 @Override
55 public boolean onCreateOptionsMenu(Menu menu) {
56 // Inflate the menu; this adds items to the action bar if it is present.
57 getMenuInflater().inflate(R.menu.activity_android_seek_bar, menu);
58 return true;
59 }
60
61 }
