目录

全局配置项功能场景

对于需要使用进程单例的场景，例如不同并发实例间需要数据保持一致的全局配置项功能，可以采用共享模块来实现。

以下示例展示了只有在Wi-Fi打开且用户登录的情况下才能进行下载的功能，具体步骤如下。

  1. 编写全局配置文件。

    import { ArkTSUtils } from '@kit.ArkTS';

'use shared'

@Sendable
class Config {
  public lock: ArkTSUtils.locks.AsyncLock = new ArkTSUtils.locks.AsyncLock();
  public isLogin: boolean = false;
  public loginUser?: string;
  public wifiOn: boolean = false;

  async login(user: string) {
    return this.lock.lockAsync(() => {
      this.isLogin = true;
      this.loginUser = user;
    }, ArkTSUtils.locks.AsyncLockMode.EXCLUSIVE)
  }

  async logout() {
    return this.lock.lockAsync(() => {
      this.isLogin = false;
      this.loginUser = '';
    }, ArkTSUtils.locks.AsyncLockMode.EXCLUSIVE)
  }

  async getIsLogin(): Promise<boolean> {
    return this.lock.lockAsync(() => {
      return this.isLogin;
    }, ArkTSUtils.locks.AsyncLockMode.SHARED)
  }

  async getUser(): Promise<string> {
    return this.lock.lockAsync(() => {
      return this.loginUser!;
    }, ArkTSUtils.locks.AsyncLockMode.SHARED)
  }

  async setWifiState(state: boolean) {
    return this.lock.lockAsync(() => {
      this.wifiOn = state;
    }, ArkTSUtils.locks.AsyncLockMode.EXCLUSIVE)
  }

  async isWifiOn() {
    return this.lock.lockAsync(() => {
      return this.wifiOn;
    }, ArkTSUtils.locks.AsyncLockMode.SHARED)
  }
}

export let config = new Config();

  2. UI主线程及子线程访问全局配置项。

    import { config } from './Config';
import { taskpool } from '@kit.ArkTS';

@Concurrent
async function download() {
  if (!await config.isWifiOn()) {
    console.info('wifi is off');
    return false;
  }
  if (!await config.getIsLogin()) {
    console.info('not login');
    return false;
  }
  console.info(`User[${await config.getUser()}] start download ...`);
  return true;
}

@Entry
@Component
struct Index {
  @State message: string = 'not login';
  @State wifiState: string = 'wifi off';
  @State downloadResult: string = '';
  input: string = '';

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
        TextInput({ placeholder: '请输入用户名' })
          .id('textInput')
          .fontSize(20)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
          .onChange((value) => {
            this.input = value;
          })
        Text('login')
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
          .onClick(async () => {
            if (!await config.getIsLogin() && this.input) {
              try {
                await config.login(this.input);
                this.message = 'login: ' + this.input;
              } catch (e) {
                console.error('login failed');
              }
            }
          })
          .backgroundColor('#cccccc')
        Text('logout')
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
          .onClick(async () => {
            if (await config.getIsLogin()) {
              try {
                await config.logout();
                this.message = 'not login';
              } catch (e) {
                console.error('logout failed');
              }
            }
          })
          .backgroundColor('#cccccc')
        Text(this.wifiState)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
        Toggle({ type: ToggleType.Switch })
          .onChange(async (isOn: boolean) => {
            await config.setWifiState(isOn)
            this.wifiState = isOn ? 'wifi on' : 'wifi off';
          })
        Text('download')
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
          .onClick(async () => {
            let ret = await taskpool.execute(download);
            this.downloadResult = ret ? 'download success' : 'download fail';
          })
        Text(this.downloadResult)
          .fontSize(20)
          .fontWeight(FontWeight.Bold)
          .alignRules({
            center: { anchor: '__container__', align: VerticalAlign.Center },
            middle: { anchor: '__container__', align: HorizontalAlign.Center }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}