public async Task<FileStreamResult> DownloadFiles(DownLoadModel input)
    {
      if (!Directory.Exists(input.pathUrl))
      {
        throw new UserFriendlyException("当前要下载的文件夹不存在或已删除");
      }
      var zipFileUrl = _configurationRoot["downLoadUrlConf:downloadZipFileUrl"];
      if (File.Exists(zipFileUrl))
      {
        File.Delete(zipFileUrl);
      }
      ZipHelper.CreateZip(input.pathUrl, zipFileUrl);
      var memoryStream = new MemoryStream();
      using (var stream = new FileStream(zipFileUrl, FileMode.Open))
      {
        await stream.CopyToAsync(memoryStream);
      }
      memoryStream.Seek(0, SeekOrigin.Begin);
      return new FileStreamResult(memoryStream, "application/octet-stream");//文件流方式，指定文件流对应的ContenType。
    }

 public static class ZipHelper
  {
    /// <summary>
    /// 压缩文件
    /// </summary>
    /// <param name="sourceFilePath"></param>
    /// <param name="destinationZipFilePath"></param>
    public static void CreateZip(string sourceFilePath, string destinationZipFilePath)
    {
      if (sourceFilePath[sourceFilePath.Length - 1] != System.IO.Path.DirectorySeparatorChar)
        sourceFilePath += System.IO.Path.DirectorySeparatorChar;

      ZipOutputStream zipStream = new ZipOutputStream(File.Create(destinationZipFilePath));
      zipStream.SetLevel(6); // 压缩级别 0-9
      CreateZipFiles(sourceFilePath, zipStream, sourceFilePath);

      zipStream.Finish();
      zipStream.Close();
    }
    /// <summary>
    /// 递归压缩文件
    /// </summary>
    /// <param name="sourceFilePath">待压缩的文件或文件夹路径</param>
    /// <param name="zipStream">
    /// <param name="staticFile"></param>
    private static void CreateZipFiles(string sourceFilePath, ZipOutputStream zipStream, string staticFile)
    {
      Crc32 crc = new Crc32();
      string[] filesArray = Directory.GetFileSystemEntries(sourceFilePath);
      foreach (string file in filesArray)
      {
        if (Directory.Exists(file))           //如果当前是文件夹，递归
        {
          CreateZipFiles(file, zipStream, staticFile);
        }

        else                      //如果是文件，开始压缩
        {
          FileStream fileStream = File.OpenRead(file);

          byte[] buffer = new byte[fileStream.Length];
          fileStream.Read(buffer, 0, buffer.Length);
          string tempFile = file.Substring(staticFile.LastIndexOf("\\") + 1);
          ZipEntry entry = new ZipEntry(tempFile);

          entry.DateTime = DateTime.Now;
          entry.Size = fileStream.Length;
          fileStream.Close();
          crc.Reset();
          crc.Update(buffer);
          entry.Crc = crc.Value;
          zipStream.PutNextEntry(entry);

          zipStream.Write(buffer, 0, buffer.Length);
        }
      }
    }
  }

 <el-button
     icon="el-icon-download"
     size="mini"
     type="primary"
     class="pull-right"
     @click="downloadFile"
    >下载文件到本地</el-button>

 downloadFile() {
    this.loading = true;
    let postData = { pathUrl: this.filePathMag };
    AjaxHelper.post(this.downLoadUrl, postData, {
     responseType: "blob",
    }).then((res) => {
     // 处理返回的文件流
     const content = res.data;
     const blob = new Blob([content], { type: "application/zip" });
     const fileName = this.tenant.name + "配置信息.zip";
     if ("download" in document.createElement("a")) {
      // 非IE下载
      const elink = document.createElement("a");
      elink.download = fileName;
      elink.style.display = "none";
      elink.href = URL.createObjectURL(blob);
      document.body.appendChild(elink);
      elink.click();
      URL.revokeObjectURL(elink.href); // 释放URL 对象
      document.body.removeChild(elink);
     } else {
      // IE10+下载
      navigator.msSaveBlob(blob, fileName);
     }
     this.loading = false;
    });
   },