下载PDF作为Blob在Chrome iOS上不起作用

在Angular 7应用程序中，我有以下用于在各种平台上下载PDF的代码

this.http.get('/api/url', {responseType: 'blob'}).pipe(map(res => {
      return {
        filename: 'filename.pdf',
        data: res
      };
    }))
      .subscribe(
        res => {
          const fileBlob = new Blob([res.data], {type: 'application/pdf'});

          if (navigator && navigator.msSaveBlob) { // IE10+
            navigator.msSaveBlob(fileBlob, res.filename);
          } else if (navigator.userAgent.match('CriOS')) { // iOS Chrome
            const reader = new FileReader();
            reader.onloadend = () => {
              window.location.href = reader.result.toString();
            };
            reader.readAsDataURL(fileBlob);
          } else if (navigator.userAgent.match(/iPad/i) || navigator.userAgent.match(/iPhone/i)) { // iOS Safari and Opera
            const url: string = URL.createObjectURL(fileBlob);
            window.location.href = url;
          } else {
            const url: string = URL.createObjectURL(fileBlob);
            const a: any = document.createElement('a');
            document.body.appendChild(a);
            a.setAttribute('style', 'display: none');
            a.href = url;
            a.download = res.filename;
            a.click();
            URL.revokeObjectURL(url);
            a.remove();
          }
        }
      );

除了Chrome iOS，下载在所有平台上都可以正常工作。我主要关注和其他一些类似的链接

我还为Chrome iOS尝试了以下案例

const reader = new FileReader();
reader.onloadend = () => {
    window.open(reader.result.toString());
};
reader.readAsDataURL(fileBlob);

还将onloadend替换为上面的onload，并尝试了两种方法。 此外，我还尝试了Safari的代码，但也失败了

---

知道我在这里遗漏了什么吗？

删除自定义chrome ios检查对我来说很有效：

        ...subscribe(response => {
            const file = new Blob([response.body], {type: 'application/pdf'});
            const fileURL = (window.URL || window['webkitURL']).createObjectURL(file);
            const fileName = 'Whatever.pdf';

            const downloadLink = document.createElement('a');
            downloadLink.href = fileURL;
            downloadLink.download = fileName;
            document.body.appendChild(downloadLink);
            downloadLink.click();
            document.body.removeChild(downloadLink);
        })