Android 设置系统亮度

/**
* 播放器Activity
*/
public class PlayerActivity extends Activity {

/**
* 系统是否自动调节亮度
*/
private boolean isAutoBrightness = false;

/**
* 系统亮度变化值
*/
private static final int SYSTEM_BRIGHTNESS_CHANGE_VALUES = 25;

/**
* 最大系统音量值
*/
private static final int MAX_SYSTEM_BRIGHTNESS_VALUES = 255;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/**
* 打开播放器界面判断系统是否设置了自动亮度
* 设置系统亮度时如果系统亮度设置了自动亮度，需要先关闭自动亮度
*/
isAutoBrightness = DeviceUtil.isAutoBrightness(this);
if (isAutoBrightness) {
DeviceUtil.stopAutoBrightness(this);
}
}

@Override
protected void onResume() {
/*
* 播放器请求屏幕常亮需要写在onResume方法中，如果写在onCreate()方法中，
* 用户在播放时按HOME后，再次回到播放器，屏幕常亮失败
*/
DeviceUtil.requireScreenOn(this);

/**
* 解决用户按HOME后回到播放器亮度模式为自动亮度  重新方法：(自动亮度打开PlayerActivity--> 按HOME --> (进入系统设置此时
* 系统亮度为非自动亮度)修改为自动亮度 --> 回到播放器)
*/
isAutoBrightness = DeviceUtil.isAutoBrightness(this);
if (isAutoBrightness) {
DeviceUtil.stopAutoBrightness(this);
}
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
int currSettingBrighiness = DeviceUtil.getSystemScreenBrightness(this);
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_UP:
// 系统亮度加
addSystemBrighiness(currSettingBrighiness);
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
// 系统亮度减
minusSystemBrighiness(currSettingBrighiness);
break;
default:
break;
}
return super.onKeyDown(keyCode, event);
}

/**
* 系统亮度加
*
* @param currSettingBrighiness
*            系统当前亮度
*/
private void addSystemBrighiness(int currSettingBrighiness) {
if (currSettingBrighiness < MAX_SYSTEM_BRIGHTNESS_VALUES
&& (currSettingBrighiness + SYSTEM_BRIGHTNESS_CHANGE_VALUES) < MAX_SYSTEM_BRIGHTNESS_VALUES) {
setSystemBrighiness = currSettingBrighiness
+ SYSTEM_BRIGHTNESS_CHANGE_VALUES;
DeviceUtil.setSystemScreenBrightness(this, setSystemBrighiness);
}
}

/**
* 系统亮度减
*
* @param currSettingBrighiness
*            系统当前亮度
*/
public void minusSystemBrighiness(int currSettingBrighiness) {
if (currSettingBrighiness >= SYSTEM_BRIGHTNESS_CHANGE_VALUES) {
setSystemBrighiness = currSettingBrighiness
- SYSTEM_BRIGHTNESS_CHANGE_VALUES;
DeviceUtil.setSystemScreenBrightness(this, setSystemBrighiness);
}
}
}

/**
* DeviceUtil 工具类
*/
public class DeviceUtil {
/**
* 获取系统亮度
* 取值在(0 -- 255)之间
*/
public static int getSystemScreenBrightness(Context context) {
int values = 0;
try {
values = Settings.System.getInt(context.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS);
} catch (SettingNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return values;
}

/**
* 设置系统亮度
* @param systemBrightness 返回的亮度值是处于0-255之间的整型数值
*/
public static boolean setSystemScreenBrightness(Context context, int systemBrightness) {
return Settings.System.putInt(context.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS,systemBrightness);
}

/**
* 系统是否自动调节亮度
* return true 是自动调节亮度   return false 不是自动调节亮度
*/
public static boolean isAutoBrightness(Activity activity){
int autoBrightness = Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
try {
autoBrightness = Settings.System.getInt(activity.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS_MODE);
} catch (SettingNotFoundException e) {
e.printStackTrace();
}
if (autoBrightness == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
return true;
} else {
return false;
}
}

/**
* 关闭系统自动调节亮度
*/
public static void stopAutoBrightness(Activity activity){
Settings.System.putInt(activity.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
}

/**
* 打开系统自动调节亮度
*/
public static void startAutoBrightness(Activity activity) {
Settings.System.putInt(activity.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
}

/**
* 请求屏幕常亮
* @param activity
*/
public static void requireScreenOn(Activity activity){
activity.getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,
WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}

/**
* 取消屏幕常亮
* @param activity
*/
public static void releaseScreenOn(Activity activity){
activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
}