#鸿蒙通关秘籍#如何使用缓存和预加载来提高鸿蒙应用响应速度？

为了提高应用的响应速度，通过设计缓存机制可以避免重复创建和销毁对象，使用预加载技术可以提前加载数据或视图，提高显示速度。在视频加载场景中，可利用AVPlayer实例缓存进行优化。

import media from '@ohos.multimedia.media';

@Entry
@Component
struct Index {
  private avPlayer: media.AVPlayer | undefined = undefined;
  private avPlayerManager: AVPlayerManager = AVPlayerManager.getInstance();

  aboutToAppear(): void {
    this.avPlayerManager.switchPlayer();
    this.avPlayer = this.avPlayerManager.getCurrentPlayer();
  }

  aboutToDisappear(): void {
    this.avPlayerManager.resetCurrentPlayer();
    this.avPlayer = undefined;
  }

  build() {
    // 组件布局
  }
}

class AVPlayerManager {
  private static instance?: AVPlayerManager;

  private player1?: media.AVPlayer;
  private player2?: media.AVPlayer;
  private currentPlayer?: media.AVPlayer;

  public static getInstance(): AVPlayerManager {
    if (!AVPlayerManager.instance) {
      AVPlayerManager.instance = new AVPlayerManager();
    }
    return AVPlayerManager.instance;
  }

  async AVPlayerManager() {
    this.player1 = await media.createAVPlayer();
    this.player2 = await media.createAVPlayer();
  }

  switchPlayer(): void {
    if (this.currentPlayer === this.player1) {
      this.currentPlayer = this.player2;
    } else {
      this.currentPlayer = this.player1;
    }
  }

  getCurrentPlayer(): media.AVPlayer | undefined {
    return this.currentPlayer;
  }

  resetCurrentPlayer(): void {
    this.currentPlayer?.pause(() => {
      this.currentPlayer?.reset();
    });
  }
}