由于修改系统 Settings 中的屏幕亮度，由于会影响到所有APP，需要申请修改Settings的权限<uses-permission * android:name="android.permission.WRITE_SETTINGS"/>，同时需要取消光感自动调节屏幕亮度的功能，设置为手动调节模式，否则光感传感器会随着光照强度的变化修改系统屏幕亮度，并且非系统签名的APP，需要用户手动授权后才可以修改背光亮度。
以下就是系统亮度的实现方式：
1、效果图
2、布局文件
<SeekBar
android:id="@+id/car_brightness"
android:layout_width="496px"
android:layout_height="80px"
android:max="100"
android:progress="0"
/>
<ImageView
android:layout_width="40px"
android:layout_height="41px"
android:layout_marginStart="385px"
android:layout_marginTop="19px"
android:src="@mipmap/icon_brightness" />
3、工具类
/**
* 屏幕亮度工具类
*/
public class BrightnessUtil {
/**
*获取系统屏幕亮度
*/
public static int getBrightness(Context context) {
int brightness = -1;
ContentResolver resolver = context.getContentResolver();
try {
brightness = Settings.System.getInt(resolver, Settings.System.SCREEN_BRIGHTNESS);
} catch (Settings.SettingNotFoundException e) {
e.printStackTrace();
}
Log.e("ccm=======>","getBrightness: "+brightness);
return brightness;
}
/**
*获取系统最大屏幕亮度
*/
public static int getMaxBrightness(Context context) {
int brightnessSettingMaximumId = context.getResources().getIdentifier("config_screenBrightnessSettingMaximum", "integer", "android");
int brightnessSettingMaximum = context.getResources().getInteger(brightnessSettingMaximumId);
Log.e("ccm=======>","getMaxBrightness: "+brightnessSettingMaximum);
return brightnessSettingMaximum;
}
/**
*调节当前屏幕亮度
*/
public static void SetSystemLight(int lightnumber, Activity activity){
Window window = activity.getWindow();//对当前窗口进行设置
WindowManager.LayoutParams layoutparams = window.getAttributes();//获取窗口属性为后面亮度做铺垫作用
layoutparams.screenBrightness =lightnumber / 255.0f;//用窗口管理（自定义的）layoutparams获取亮度值，android亮度值处于在0-255之间的整形数值
window.setAttributes(layoutparams);//设置当前窗口屏幕亮度
}
/**
* 5.修改Setting 中屏幕亮度值
*
* 修改Setting的值需要动态申请权限 <uses-permission
* android:name="android.permission.WRITE_SETTINGS"/>
* **/
public static void ModifySettingsScreenBrightness(Context context, int birghtessValue) {
// 首先需要设置为手动调节屏幕亮度模式
setScreenManualMode(context);
ContentResolver contentResolver = context.getContentResolver();
Log.e("ccm=======>", "birghtessValue: "+birghtessValue);
Settings.System.putInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS, birghtessValue);
}
/**
* 3.关闭光感，设置手动调节背光模式
*
* SCREEN_BRIGHTNESS_MODE_AUTOMATIC 自动调节屏幕亮度模式值为1
*
* SCREEN_BRIGHTNESS_MODE_MANUAL 手动调节屏幕亮度模式值为0
* **/
public static void setScreenManualMode(Context context) {
ContentResolver contentResolver = context.getContentResolver();
try {
int mode = Settings.System.getInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE);
if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
Settings.System.putInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
}
} catch (Settings.SettingNotFoundException e) {
e.printStackTrace();
}
}
}
4、实现类
private void initBrightness(){
if (!Settings.System.canWrite(QuickCircularActivity.this)) {
Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS, Uri.parse("package:" + getPackageName()));
startActivityForResult(intent, REQUEST_CODE_WRITE_SETTINGS);
}
//将系统最大屏幕亮度值设为seekbar的最大进度值
mCarBrightness.setMax(BrightnessUtil.getMaxBrightness(QuickCircularActivity.this));
//将系统当前屏幕亮度值设为seekbar当前进度值
Log.e("ccm=======>", "setOneProgress: " + BrightnessUtil.getBrightness(QuickCircularActivity.this));
int brightness = BrightnessUtil.getBrightness(QuickCircularActivity.this);
mCarBrightness.setProgress(brightness);
mCarBrightness.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
Log.e("ccm=======>", "onProgressChanged: " + progress);
ModifySettingsScreenBrightness(QuickCircularActivity.this,progress);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
