基于HarmonyOS的屏幕亮度调节与跨设备同步实现 原创

基于HarmonyOS的屏幕亮度调节与跨设备同步实现

一、项目概述

本项目基于HarmonyOS的显示管理能力，开发一个支持多设备同步的屏幕亮度调节应用。参考《鸿蒙跨端U同步:同一局游戏中多设备玩家昵称/头像显示》中的分布式技术，实现屏幕亮度在多设备间的协同调节。

图1：亮度调节系统架构（包含UI层、系统接口层和分布式同步层）

二、核心功能实现
亮度控制与系统接口（ArkTS）

// 亮度管理服务
class BrightnessManager {
private static instance: BrightnessManager;
private brightness: number = 50; // 默认亮度50%
private autoMode: boolean = false;

static getInstance(): BrightnessManager {
if (!BrightnessManager.instance) {
BrightnessManager.instance = new BrightnessManager();
return BrightnessManager.instance;

constructor() {

this.initBrightness();

// 初始化亮度设置

private initBrightness() {
try {
const display = display.getDefaultDisplaySync();
this.brightness = display.getBrightness();
this.autoMode = display.isAutoBrightness();
catch (error) {

  console.error('获取亮度设置失败:', error);

}

// 设置手动亮度
setManualBrightness(value: number): void {
this.brightness = Math.max(0, Math.min(100, value));
this.autoMode = false;

try {
  const display = display.getDefaultDisplaySync();
  display.setBrightness(this.brightness);
  display.setAutoBrightness(false);

catch (error) {

  console.error('设置亮度失败:', error);

}

// 切换自动亮度模式
toggleAutoBrightness(): void {
this.autoMode = !this.autoMode;

try {
  const display = display.getDefaultDisplaySync();
  display.setAutoBrightness(this.autoMode);

catch (error) {

  console.error('设置自动亮度失败:', error);

}

// 获取当前亮度
getCurrentBrightness(): number {
return this.brightness;
// 是否自动亮度模式

isAutoMode(): boolean {
return this.autoMode;
}

分布式数据同步实现（ArkTS）

// 亮度同步服务
class BrightnessSyncService {
private static instance: BrightnessSyncService;
private distObject: distributedDataObject.DataObject;

static getInstance(): BrightnessSyncService {
if (!BrightnessSyncService.instance) {
BrightnessSyncService.instance = new BrightnessSyncService();
return BrightnessSyncService.instance;

constructor() {

// 初始化分布式数据对象
this.distObject = distributedDataObject.create({
  brightness: 50,
  autoMode: false,
  sourceDevice: ''
});

// 监听数据变化
this.distObject.on('change', (fields: string[]) => {
  if (fields.includes('brightness') || fields.includes('autoMode')) {
    this.handleBrightnessUpdate();

});

// 同步亮度设置

syncBrightness(brightness: number, autoMode: boolean): void {
this.distObject.brightness = brightness;
this.distObject.autoMode = autoMode;
this.distObject.sourceDevice = deviceInfo.deviceId;

// 同步到已连接设备
const targetDevices = deviceManager.getConnectedDevices()
  .map(d => d.deviceId)
  .filter(id => id !== deviceInfo.deviceId);

if (targetDevices.length > 0) {
  this.distObject.setDistributed(targetDevices);

}

// 处理亮度更新
private handleBrightnessUpdate(): void {
const remoteBrightness = this.distObject.brightness as number;
const remoteAutoMode = this.distObject.autoMode as boolean;
const remoteDevice = this.distObject.sourceDevice as string;

// 只处理来自其他设备的更新
if (remoteDevice !== deviceInfo.deviceId) {
  const brightnessManager = BrightnessManager.getInstance();
  
  if (remoteAutoMode) {
    brightnessManager.toggleAutoBrightness();

else {

    brightnessManager.setManualBrightness(remoteBrightness);

}

}

UI界面实现（ArkTS）

// 主页面组件
@Entry
@Component
struct BrightnessControlPage {
@State currentBrightness: number = 50;
@State autoMode: boolean = false;
@State connectedDevices: number = 0;

private brightnessManager = BrightnessManager.getInstance();
private brightnessSync = BrightnessSyncService.getInstance();

aboutToAppear() {
this.currentBrightness = this.brightnessManager.getCurrentBrightness();
this.autoMode = this.brightnessManager.isAutoMode();

// 监听设备连接变化
deviceManager.on('deviceStateChange', () => {
  this.connectedDevices = deviceManager.getConnectedDevices().length;
});

this.connectedDevices = deviceManager.getConnectedDevices().length;

build() {

Column() {
  // 标题栏
  Row() {
    Text('亮度调节')
      .fontSize(24)
      .fontWeight(FontWeight.Bold)
      
    DeviceSyncIndicator()

.width(‘100%’)

  .padding(16)
  
  // 自动亮度开关
  Row() {
    Text('自动亮度')
      .fontSize(18)
      .layoutWeight(1)
      
    Toggle({ type: ToggleType.Switch, isOn: this.autoMode })
      .onChange((isOn: boolean) => {
        this.autoMode = isOn;
        this.brightnessManager.toggleAutoBrightness();
        this.brightnessSync.syncBrightness(this.currentBrightness, this.autoMode);
      })

.width(‘90%’)

  .padding(16)
  
  // 亮度调节滑块
  if (!this.autoMode) {
    Column() {
      Slider({
        value: this.currentBrightness,
        min: 0,
        max: 100,
        step: 1,
        style: SliderStyle.OutSet
      })
      .width('90%')
      .onChange((value: number) => {
        this.currentBrightness = value;
        this.brightnessManager.setManualBrightness(value);
        this.brightnessSync.syncBrightness(value, this.autoMode);
      })
      
      Row() {
        Text('0%')
          .fontSize(14)
          
        Text(${this.currentBrightness}%)
          .fontSize(16)
          .fontWeight(FontWeight.Bold)
          .layoutWeight(1)
          .textAlign(TextAlign.Center)
          
        Text('100%')
          .fontSize(14)

.width(‘90%’)

      .margin({ top: 8 })

.width(‘100%’)

    .margin({ top: 20 })

// 设备同步面板

  DeviceSyncPanel()

.height(‘100%’)

.backgroundColor('#F5F5F5')

}

// 设备同步指示器组件
@Component
struct DeviceSyncIndicator {
@State connectedDevices: number = 0;

aboutToAppear() {
deviceManager.on(‘deviceStateChange’, () => {
this.connectedDevices = deviceManager.getConnectedDevices().length;
});

this.connectedDevices = deviceManager.getConnectedDevices().length;

build() {

Row() {
  Image($r('app.media.ic_devices'))
    .width(20)
    .height(20)
    
  Text(${this.connectedDevices})
    .fontSize(16)
    .margin({ left: 4 })

}

// 设备同步面板组件

@Component
struct DeviceSyncPanel {
@State deviceList: deviceManager.DeviceInfo[] = [];

aboutToAppear() {
this.deviceList = deviceManager.getConnectedDevices();
deviceManager.on(‘deviceStateChange’, () => {
this.deviceList = deviceManager.getConnectedDevices();
});
build() {

Column() {
  Text('已连接设备')
    .fontSize(16)
    .fontColor('#666666')
    .margin({ bottom: 8 })
  
  if (this.deviceList.length > 0) {
    Column() {
      ForEach(this.deviceList, (device: deviceManager.DeviceInfo) => {
        DeviceItem({ device: device })
      })

.width(‘100%’)

    .padding(12)
    .backgroundColor('#FFFFFF')
    .borderRadius(8)

else {

    Text('未连接其他设备')
      .fontSize(14)
      .fontColor('#999999')

}

.width('90%')
.padding(16)
.margin({ top: 20 })

}

// 设备项组件
@Component
struct DeviceItem {
@Prop device: deviceManager.DeviceInfo;

build() {
Row() {
Image($r(‘app.media.ic_device’))
.width(24)
.height(24)
.margin({ right: 12 })

  Text(this.device.deviceName)
    .fontSize(16)
    .layoutWeight(1)
    
  if (this.device.deviceId === deviceInfo.deviceId) {
    Text('本机')
      .fontSize(14)
      .fontColor('#999999')

}

.width('100%')
.height(48)

}

三、关键功能说明
亮度控制实现原理

获取显示接口：

  const display = display.getDefaultDisplaySync();

设置亮度值：

  display.setBrightness(value); // 0-100范围

自动亮度控制：

  display.setAutoBrightness(true/false);

分布式同步策略

同步方式 触发条件 数据内容 冲突解决

即时同步 亮度值变化 亮度值+模式 最后操作优先
状态同步 设备连接 当前亮度状态 时间戳比对

多设备同步流程

sequenceDiagram
participant DeviceA
participant DeviceB
participant 分布式数据管理

DeviceA->>DeviceA: 用户调节亮度
DeviceA->>分布式数据管理: 同步亮度设置
分布式数据管理->>DeviceB: 分发亮度更新
DeviceB->>DeviceB: 应用新亮度设置

四、项目扩展与优化
功能扩展建议

情景模式：

  enum BrightnessPreset {
 READING = 60,
 MOVIE = 40,
 OUTDOOR = 80

定时调节：

  setTimedBrightness(dayValue: number, nightValue: number) {
 // 根据时间自动切换

环境光传感器：

  sensor.getSensorManager().getDefaultSensor(sensor.SensorId.AMBIENT_LIGHT)

性能优化建议

同步节流：

  // 添加500ms的同步节流

private lastSyncTime: number = 0;
if (Date.now() - this.lastSyncTime > 500) {
this.syncBrightness();
this.lastSyncTime = Date.now();

差异同步：

  // 只在亮度变化超过5%时同步

if (Math.abs(newValue - lastSyncedValue) >= 5) {
this.syncBrightness();

五、测试方案
测试用例设计

测试类型 测试场景 验证点

功能测试 手动调节亮度 屏幕亮度实际变化
功能测试 切换自动模式 自动亮度是否生效
同步测试 多设备调节 亮度设置同步一致
性能测试 快速滑动调节 无卡顿和延迟
兼容测试 不同设备 亮度范围适配

自动化测试示例

// 亮度控制测试
describe(‘BrightnessControl Tests’, () => {
let brightnessManager: BrightnessManager;

before(() => {
brightnessManager = BrightnessManager.getInstance();
});

it(‘should set manual brightness’, () => {
brightnessManager.setManualBrightness(75);
expect(brightnessManager.getCurrentBrightness()).toBe(75);
expect(brightnessManager.isAutoMode()).toBeFalsy();
});

it(‘should sync brightness across devices’, () => {
const syncService = BrightnessSyncService.getInstance();
syncService.syncBrightness(60, false);

expect(brightnessManager.getCurrentBrightness()).toBe(60);
expect(brightnessManager.isAutoMode()).toBeFalsy();

});
});

六、总结

本项目基于HarmonyOS实现了具有以下特点的屏幕亮度调节系统：
精确的亮度控制：支持手动和自动两种调节模式

智能的多设备同步：实时同步亮度设置到所有设备

直观的用户界面：清晰的滑块控制和状态显示

完善的权限管理：正确处理系统权限需求

通过参考《鸿蒙跨端U同步:同一局游戏中多设备玩家昵称/头像显示》的技术方案，我们验证了HarmonyOS在设备控制和分布式协同方面的强大能力，为开发者提供了构建系统级控制应用的实践参考。

注意事项：
实际开发中需要申请ohos.permission.DISPLAY_MANAGER权限

考虑不同设备的亮度范围差异

生产环境需要添加更完善的错误处理

可根据具体需求调整同步策略和UI交互