C# 使用API从Azure blob下载

我需要使用API将PDF或excel文件从azure blob存储管道传输到前端。我正在使用，然后将其转换为内存流，将其发送回用户

这是我的控制器

[AllowAnonymous]
[HttpGet]
[Route("GetFiles")]
public HttpResponseMessage GetFiles()
{
        const string StorageAccountName = "nameofAccount";
        const string StorageAccountKey = "TheKey";
        try
        {
          var storageAccount = new CloudStorageAccount(new StorageCredentials(StorageAccountName, StorageAccountKey), true);// login to azure and storage Account
          
          var bloblClinet = storageAccount.CreateCloudBlobClient();// get blob client refernce

          var container = bloblClinet.GetContainerReference("crmtestblob");// get container refernce 

          var blob = container.GetBlockBlobReference("test.xlsx");
          long fileByteLength = blob.Properties.Length;// this return -1 
          byte[] fileContent = new byte[100000];

          var MyArray = blob.DownloadToByteArray(fileContent, 0);
            
          HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);


          var stream = new MemoryStream(MyArray);//application/octet-stream
            result.Content = new StreamContent(stream);//application/vnd.ms-excel
          result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
          result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
          {
              FileName = "test.xlsx"
          };
          return result;

        }
        catch (Exception ex)
        {
           

            
            return new HttpResponseMessage(HttpStatusCode.InternalServerError);
        }

    }

我得到200的答复 但是没有发送任何文件，或者文件已损坏

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任何帮助都会很好

您错误地使用了函数

DownloadToByteArray

，导致了您的问题

根据官方API参考，函数的返回结果是读入缓冲区的字节总数，而不是blob内容

下面有两个这样的线程，我认为它们的答案对您修复它很有帮助

用于打开可读流作为响应流内容

var stream = await blob.OpenReadAsync();
result.Content = new StreamContent(stream);

使用sas令牌将请求重定向到blob url

var sasToken = blob.GetSharedAccessSignature(new SharedAccessBlobPolicy()
{
    Permissions = SharedAccessBlobPermissions.Read,
    SharedAccessExpiryTime = DateTime.UtcNow.AddHours(1)//Assuming you want the link to expire after 1 hour
});
var blobUrl = string.Format("{0}{1}", blob.Uri.AbsoluteUri, sasToken);
var response = Request.CreateResponse(HttpStatusCode.Moved);
response.Headers.Location = new Uri(bloburl);

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我需要从azure存储下载一个文件。