提升应用冷启动速度

    "abilities": [
      {
        "name": "EntryAbility",
        "srcEntry": "./ets/entryability/EntryAbility.ets",
        "description": "$string:EntryAbility_desc",
        "icon": "$media:icon",
        "label": "$string:EntryAbility_label",
        "startWindowIcon": "$media:startIcon", // 在这里修改启动页图标，建议不要超过256像素x256像素
        "startWindowBackground": "$color:start_window_background",
        "exported": true,
        "skills": [
          {
            "entities": [
              "entity.system.home"
            ],
            "actions": [
              "action.system.home"
            ]
          }
        ]
      }
    ]

// 优化减少import的模块
// import ability from '@ohos.ability.ability';
// import dataUriUtils from '@ohos.ability.dataUriUtils';
// import errorCode from '@ohos.ability.errorCode';
// import featureAbility from '@ohos.ability.featureAbility';
// import particleAbility from '@ohos.ability.particleAbility';
// import wantConstant from '@ohos.ability.wantConstant';
// import common from '@ohos.app.ability.common';
// import Configuration from '@ohos.app.ability.Configuration';
// import contextConstant from '@ohos.app.ability.contextConstant';
// import ConfigurationConstant from '@ohos.app.ability.ConfigurationConstant';
// import FormExtensionAbility from '@ohos.app.form.FormExtensionAbility';
// import GesturePath from '@ohos.accessibility.GesturePath';
// import GesturePoint from '@ohos.accessibility.GesturePoint';
// import distributedAccount from '@ohos.account.distributedAccount';
// import osAccount from '@ohos.account.osAccount';

import AbilityConstant from '@ohos.app.ability.AbilityConstant';
import UIAbility from '@ohos.app.ability.UIAbility';
import Want from '@ohos.app.ability.Want';
import window from '@ohos.window';
import logger from '../common/Logger';

export default class EntryAbility extends UIAbility {
  // ...
}

const LARGE_NUMBER = 10000000;
const DELAYED_TIME = 1000;

export default class MyAbilityStage extends AbilityStage {
  onCreate(): void {
    // 耗时操作
    // this.computeTask();
    this.computeTaskAsync(); // 异步任务
  }

  onAcceptWant(want: Want): string {
    // 仅specified模式下触发
    return 'MyAbilityStage';
  }

  computeTask(): void {
    let count = 0;
    while (count < LARGE_NUMBER) {
      count++;
    }
  }

  private computeTaskAsync(): void {
    setTimeout(() => { // 这里使用setTimeout来实现异步延迟运行
      this.computeTask();
    }, DELAYED_TIME);
  }
}

const LARGE_NUMBER = 10000000;
const DELAYED_TIME = 1000;

export default class EntryAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
    logger.info('Ability onCreate');
    // 耗时操作
    // this.computeTask();
    this.computeTaskAsync(); // 异步任务
  }

  onDestroy(): void {
    logger.info('Ability onDestroy');
  }

  onWindowStageCreate(windowStage: window.WindowStage): void {
    logger.info('Ability onWindowStageCreate');

    windowStage.loadContent('pages/Index', (err, data) => {
      if (err.code) {
        logger.error('Failed to load the content. Cause: ' + JSON.stringify(err) ?? '');
        return;
      }
      logger.info('Succeeded in loading the content. Data: ' + JSON.stringify(data) ?? '');
    });

    // 耗时操作
    // this.computeTask();
    this.computeTaskAsync(); // 异步任务
  }

  onWindowStageDestroy(): void {
    logger.info('Ability onWindowStageDestroy');
  }

  onForeground(): void {
    logger.info('Ability onForeground');
    // 耗时操作
    // this.computeTask();
    this.computeTaskAsync(); // 异步任务
  }

  onBackground(): void {
    logger.info('Ability onBackground');
  }

  computeTask(): void {
    let count = 0;
    while (count < LARGE_NUMBER) {
      count++;
    }
  }

  private computeTaskAsync(): void {
    setTimeout(() => { // 这里使用setTimeout来实现异步延迟运行
      this.computeTask();
    }, DELAYED_TIME);
  }
}

const LARGE_NUMBER = 10000000;
const DELAYED_TIME = 1000;

@Entry
@Component
struct Index {
  @State private text: string = "";
  private count: number = 0;

  aboutToAppear() {
    // 耗时操作
    // this.computeTask();
    this.computeTaskAsync(); // 异步任务
    let context = getContext(this) as Context;
    this.text = context.resourceManager.getStringSync($r('app.string.startup_text'));
  }

  build() {
    Column({ space: 10 }) {
      Text(this.text).fontSize(50)
    }
    .width('100%')
    .height('100%')
    .padding(10)
  }

  computeTask(): void {
    this.count = 0;
    while (this.count < LARGE_NUMBER) {
      this.count++;
    }
    let context = getContext(this) as Context;
    this.text = context.resourceManager.getStringSync($r('app.string.task_text'));
  }

  // 运算任务异步处理
  private computeTaskAsync(): void {
    setTimeout(() => { // 这里使用setTimeout来实现异步延迟运行
      this.computeTask();
    }, DELAYED_TIME);
  }
}