Android调节屏幕亮度实现代码

     private void screenBrightness_check()     {          //先关闭系统的亮度自动调节          try          {              if(android.provider.Settings.System.getInt(getContentResolver(),android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE) == android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC)              {                       android.provider.Settings.System.putInt(getContentResolver(),                        android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE,                        android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);              }          }          catch (SettingNotFoundException e)          {              // TODO Auto-generated catch block              e.printStackTrace();          }          //获取当前亮度,获取失败则返回255          intScreenBrightness=(int)(android.provider.Settings.System.getInt(getContentResolver(),                   android.provider.Settings.System.SCREEN_BRIGHTNESS,                   255));          //文本、进度条显示          mSeekBar_light.setProgress(intScreenBrightness);          mTextView_light.setText(""+intScreenBrightness*100/255);              }

//屏幕亮度     private void setScreenBritness(int brightness)     {          //不让屏幕全暗          if(brightness<=1)          {              brightness=1;          }          //设置当前activity的屏幕亮度          WindowManager.LayoutParams lp = this.getWindow().getAttributes();          //0到1,调整亮度暗到全亮          lp.screenBrightness = Float.valueOf(brightness/255f);           this.getWindow().setAttributes(lp);              //保存为系统亮度方法1          android.provider.Settings.System.putInt(getContentResolver(),                   android.provider.Settings.System.SCREEN_BRIGHTNESS,                   brightness);                   //保存为系统亮度方法2//        Uri uri = android.provider.Settings.System.getUriFor("screen_brightness"); //        android.provider.Settings.System.putInt(getContentResolver(), "screen_brightness", brightness);  //        // resolver.registerContentObserver(uri, true, myContentObserver); //        getContentResolver().notifyChange(uri, null);                   //更改亮度文本显示          mTextView_light.setText(""+brightness*100/255);     }