如何在Angular 5中解析和播放数据库中的Blob/Binary数据

// 后端代码示例（使用Express框架）
app.get('/api/blobData', (req, res) => {
  // 查询数据库，获取Blob/Binary数据
  const blobData = ...; // 从数据库中获取Blob/Binary数据

  // 将Blob/Binary数据作为响应发送到前端
  res.send(blobData);
});

// 前端代码示例（Angular 5组件）
import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-blob-player',
  template: `
    <div *ngIf="blobData">
      <img *ngIf="isImage" [src]="blobData" alt="Blob Image">
      <audio *ngIf="isAudio" [src]="blobData" controls></audio>
      <video *ngIf="isVideo" [src]="blobData" controls></video>
    </div>
  `
})
export class BlobPlayerComponent {
  blobData: any;
  isImage: boolean;
  isAudio: boolean;
  isVideo: boolean;

  constructor(private http: HttpClient) {
    this.fetchBlobData();
  }

  fetchBlobData() {
    this.http.get('api/blobData', { responseType: 'blob' })
      .subscribe((data: Blob) => {
        // 根据Blob数据的类型，判断并设置合适的播放组件
        if (data.type.startsWith('image/')) {
          this.blobData = URL.createObjectURL(data);
          this.isImage = true;
        } else if (data.type.startsWith('audio/')) {
          this.blobData = URL.createObjectURL(data);
          this.isAudio = true;
        } else if (data.type.startsWith('video/')) {
          this.blobData = URL.createObjectURL(data);
          this.isVideo = true;
        }
      });
  }
}