Android 定时自动暗屏

话不多说，直接看代码吧！

    // 最大的屏幕亮度   
    private float maxLight;
    // 当前的亮度  
    private float currentLight;
    // 用来控制屏幕亮度  
    private Handler lightHandler;
    // 60秒时间不点击屏幕，屏幕变暗 
    private long delayTime = 60 * 1000L; 
    
    
    protected void onCreate() {
        
        // 保持屏幕常亮
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,
                WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
                
        // 屏幕亮度控制
        lightHandler = new Handler(Looper.getMainLooper());  
        maxLight = getLightness(); 
        
        
    }
    
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (currentLight == 1) {
            startSleepTask();
            return false;
        }
        startSleepTask();  
        return super.dispatchTouchEvent(ev);
    }
    
    /** 
     * 获取亮度 
     */  
    private float getLightness() {
        WindowManager.LayoutParams localLayoutParams = this.getWindow().getAttributes();  
        return localLayoutParams.screenBrightness;  
    }
    
    /** 
     * 设置亮度  
     */  
    private void setLightness(int light) {  
        currentLight = light;  
        WindowManager.LayoutParams localLayoutParams = this.getWindow().getAttributes();
        localLayoutParams.screenBrightness = (light / 255.0F);
        this.getWindow().setAttributes(localLayoutParams);
    }
    
    /** 
     * 开启休眠任务 
     */  
    private void startSleepTask() {  
        setLightness((int) maxLight);  
        stopSleepTask();
        lightHandler.postDelayed(sleepWindowTask, delayTime);
    }  
  
    /** 
     * 结束休眠任务 
     */  
    private void stopSleepTask() {  
        lightHandler.removeCallbacks(sleepWindowTask);  
    }  
  
    /** 
     * 休眠任务 
     */ 
    Runnable sleepWindowTask = new Runnable() {  
        @Override  
        public void run() {
            setLightness(1);  
        }  
    };