Android：用Seekbar来调节屏幕亮度

 
 3 
 4 
 5 import com.dh.shoudiantong.screendatils.VerticalSeekBar;
 6 
 7 import android.app.Activity;
 8 import android.content.Context;
 9 import android.os.Bundle;
10 import android.view.MotionEvent;
11 import android.view.Window;
12 import android.view.WindowManager;
13 import android.widget.RelativeLayout;
14 import android.widget.SeekBar;
15 import android.widget.SeekBar.OnSeekBarChangeListener;
16 
17 
18 
19 public class ScreenActivity extends Activity{
20 
21     private RelativeLayout mylayout;//布局
22     Context context;
23     private int Max_Brightness = 255;//进度条的最大值
24     private VerticalSeekBar vSeekBar = null;//调节亮度的进度条
25     private float fBrightness = 0.0f;//亮度值
26     private WindowManager.LayoutParams lp = null;//窗口处理器的参数类
27     @Override
28     protected void onCreate(Bundle savedInstanceState) {
29         // TODO Auto-generated method stub
30         super.onCreate(savedInstanceState);
31         HideStatusBase();
32         setContentView(R.layout.screen_activity);
33         mylayout=(RelativeLayout)findViewById(R.id.mylayout);        
34         
35         vSeekBar = (VerticalSeekBar) findViewById(R.id.verticalSeekBar);
36         vSeekBar.setMax(Max_Brightness);
37         vSeekBar.setProgress(Max_Brightness);//默认进度值为最大
38         
39         vSeekBar.setOnSeekBarChangeListener(new SeekBarChangedListener());
40        //默认屏幕为最大亮度
41         lp = getWindow().getAttributes();
42         fBrightness = (float) vSeekBar.getProgress() / (float)Max_Brightness;
43         lp.screenBrightness =fBrightness;
44         getWindow().setAttributes(lp);
45         lp.flags |= WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
46 
47     }    
48     class SeekBarChangedListener implements OnSeekBarChangeListener{
49         @Override
50         public void onProgressChanged(SeekBar seekBar, int progress,
51                 boolean fromUser) {
52             // TODO Auto-generated method stub
53             if(progress<1) progress=1;//此处是为了避免screenbrightness=0，从而导致屏幕自动休眠锁屏
54             fBrightness = (float) progress/ (float)Max_Brightness;
55             lp.screenBrightness =fBrightness;
56             getWindow().setAttributes(lp);
57         }
58 
59         @Override
60         public void onStartTrackingTouch(SeekBar seekBar) {
61             // TODO Auto-generated method stub
62             
63         }
64 
65         @Override
66         public void onStopTrackingTouch(SeekBar seekBar) {
67             // TODO Auto-generated method stub
68             
69         }
70         
71     }
72     /**
73      * 屏幕点击事件显示菜单
74      */
75     @Override
76     public boolean onTouchEvent(MotionEvent event){
77 
78         return false;
79     }
80     /**
81      * 全屏设置
82      */
83     private void HideStatusBase()
84     {
85         requestWindowFeature(Window.FEATURE_NO_TITLE);
86         int flag=WindowManager.LayoutParams.FLAG_FULLSCREEN;
87         Window myWindow=this.getWindow();
88         myWindow.setFlags(flag,flag);
89     }
90 
91 }
92     
93

效果图：

lp.flags |= WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
是为了避免屏幕进入休眠状态

注意：当SeekBrightness=0时，屏幕会自动休眠锁屏；为了解决这个问题，我将progress小于1时设为1；

以上仅为本人为了记录，方便以后查略；若有错误，请不吝指正。