Angular 7-如何从文件协议下载txt文件

Question

我确定没有直接方法可以从文件协议中下载文件，例如file：//abc.cmp.com/folder/xyz.txt，所以我尝试使用httpClient获取文件，转换为blob然后下载。 但这也行不通，并出现如下错误：

zone.js:3243 Access to XMLHttpRequest at 'file://abc.cmp.com/folder/xyz.txt' from origin 'http://localhost:4200' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.

示例代码：

sample.html

<td><a [routerLink] = [] (click)="download('file://abc.cmp.com/folder/xyz.txt')">file://abc.cmp.com/folder/xyz.txt')</a></td>

sample.component.ts：

    download(url){
        let  a = document.createElement("a");
        document.body.appendChild(a);
        let data  = this.sampleService.getFileContent(url);
        let file = new Blob(data, {type:'text/plain'});
          let fileURL = window.URL.createObjectURL(file);
          a.href = fileURL;
          a.download = 'log';
          a.click();
      }

sample.service.ts：

    getFileContent(url) {
        return this.httpClient.get(url)
            .subscribe(data => console.log(data));
      }

如果有办法解决这个问题，那就太好了。