Azure 云存储 SDK UploadFromStreamAsync 不起作用

Question

我正在尝试将文件上传到 .Net Core 2.1 中的 Azure blob 存储。下面是我的代码。

IFormFileCollection files = formCollection.Files;

foreach (var file in files)
{
    if (file.Length > 0)
    {
        _azureCloudStorage.UploadContent(cloudBlobContainer, file.OpenReadStream(), file.FileName);
    }
}

UploadContent 实现-

public async void UploadContent(CloudBlobContainer containerReference, Stream contentStream, string blobName)
{
    try
    {
        using (contentStream)
        {
            var blockBlobRef = containerReference.GetBlockBlobReference(blobName);
            //await containerReference.SetPermissionsAsync(new BlobContainerPermissions
            //{
            //    PublicAccess = BlobContainerPublicAccessType.Blob
            //});
            await blockBlobRef.UploadFromStreamAsync(contentStream);
        }
    }
    catch(Exception ex)
    {
        //Error here
    }
}

代码执行时出现以下错误-

{System.ObjectDisposedException：无法访问已关闭的文件。在 System.IO.FileStream.get_Position() 在 Microsoft.AspNetCore.WebUtilities.FileBufferingReadStream.get_Position() 在 Microsoft.AspNetCore.Http.Internal.ReferenceReadStream.VerifyPosition() 在 Microsoft.AspNetCore.Http.Internal.ReferenceReadStream.ReadAsync（字节[] 缓冲区，Int32 偏移量，Int32 计数，CancellationToken 取消令牌）在 Microsoft.WindowsAzure.Storage.Core.Util.StreamExtensions.WriteToAsync[T]（流 stream, Stream toStream, IBufferManager bufferManager, Nullable1 copyLength, Nullable1 maxLength, Boolean calculateMd5, ExecutionState1 executionState, StreamDescriptor streamCopyState, CancellationToken token) in C:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\Common\Core\Util\StreamExtensions.cs:line 301 at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.UploadFromStreamAsyncHelper(Stream source, Nullable1 长度，AccessCondition accessCondition， BlobRequestOptions 选项，OperationContext operationContext， IProgress1 progressHandler, CancellationToken cancellationToken) in C:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\WindowsRuntime\Blob\CloudBlockBlob.cs:line 352 at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.UploadFromStreamAsyncHelper(Stream source, Nullable1 长度，AccessCondition accessCondition， BlobRequestOptions 选项，OperationContext operationContext， C:\Program Files 中的 CancellationToken cancelToken) (x86)\Jenkins\workspace\release_dotnet_master\Lib\WindowsRuntime\Blob\CloudBlockBlob.cs:line 290 在 Common.AzureCloudStorage.UploadContent（CloudBlobContainer containerReference, Stream contentStream, String blobName)

对我有用的替代解决方案： adding to azure blob storage with stream

请问有什么帮助吗？如果我可以提供更多详细信息，请告诉我。

Answer 1

我的解决方案是等到任务完成后再继续，例如

    private async void SaveAsync(IFormFile file)
    {
        CloudBlockBlob blob = this.blobContainer.GetBlockBlobReference(file.FileName);
        var task = blob.UploadFromStreamAsync(file.OpenReadStream(), file.Length);

        while (task.IsCompleted == false) {
            Thread.Sleep(1000);
        }

    }

也许传递长度也有帮助？

Answer 2

我的解决方案是包含文件长度并将位置设置为 0。

MemoryStream outStr = new MemoryStream();
CloudBlockBlob myBlob = container.GetBlockBlobReference(name);
outStr.Position = 0;
await myBlob.UploadFromStreamAsync(outStr, outStr.Length);

Answer 3

同样的问题，几年后（WindowsAzure.Storage 版本 3.0.3.0，targetFramework net45）。
同步 UploadFromStream 有效，UploadFromStreamAsync 无效。 我会投票赞成怀疑 Azure SDK 不完善异步版本，而不是 sdk 使用不足。而且，我也是一位相当有经验的开发人员 - 经验丰富，不会时不时地绊倒微软声明的一项功能，但在仔细审查时却无法使用。
其他异步方法也一样（例如 SetPropertiesAsync）。我一直在调试我的方法（如下），并且在每个 *Async 方法之后都丢失了断点 - 这就是我想出的方法。出于好奇，将 UploadFromStreamAsync => UploadFromStream，然后将 SetPropertiesAsync 更改为 SetProperties。

    public async Task StoreItem(string filename, MemoryStream content, string contentType, ICloudBlob cloudBlob)
{
    cloudBlob.UploadFromStream(content); //this line works
    //await cloudBlob.UploadFromStreamAsync(content); //doesn't work
    cloudBlob.Properties.ContentType = contentType;
    cloudBlob.SetProperties();
    //await cloudBlob.SetPropertiesAsync(); //doesn't work either
}

Answer 4

将位置设置为 0 并将流长度传递给 UploadFromStreamAsync() 解决了我的问题（文件没有上传，即使容器已经存在）。

using (var stream = file.OpenReadStream())
{
    var fileBlob = container.GetBlockBlobReference(fileName);
    stream.Position = 0;
    fileBlob.UploadFromStreamAsync(stream, stream.Length);
}

Answer 5

我已经测试了你的方法UploadContent，效果很好。

我猜你的问题可能是你得到的文件集合。

这是我的代码供您参考：

using ConsoleAppCore.DAL;
using Microsoft.Azure.Storage;
using Microsoft.Azure.Storage.Blob;
using System;
using System.IO;

namespace ConsoleAppCore
{
    class Program
    {
        static void Main(string[] args)
        {
            Run();
            Console.WriteLine("Success");
            Console.ReadLine();
        }

        public static void Run()
        {
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse("DefaultEndpointsProtocol=https;AccountName=xxxxx;AccountKey=O7xB6ebGq8e86XQSy2vkvSi/x/exxxxxxxxxxkly1DsQPYY5dF2JrAVHtBozbJo29ZrrGJA==;BlobEndpoint=https://xxxx.blob.core.windows.net/;QueueEndpoint=https://xxxx.queue.core.windows.net/;TableEndpoint=https://xxxx.table.core.windows.net/;FileEndpoint=https://xxxx.file.core.windows.net/;");

            CloudBlobClient cloudBlobClient = storageAccount.CreateCloudBlobClient();
            CloudBlobContainer container = cloudBlobClient.GetContainerReference("containertest");

            container.CreateIfNotExists();
            DirectoryInfo dir = new DirectoryInfo("E://Test");

            foreach (FileInfo file in dir.GetFiles())
            {

                BlobStorage.UploadContent(container, file.OpenRead(), file.Name);

            }
        }


    }
}

还有我的BlobStorage 类中的UploadContent 方法：

using Microsoft.Azure.Storage.Blob;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace ConsoleAppCore.DAL
{
    public class BlobStorage
    {
        public static async void UploadContent(CloudBlobContainer containerReference, Stream contentStream, string blobName)
        {
            try
            {
                using (contentStream)
                {

                    var blockBlobRef = containerReference.GetBlockBlobReference(blobName);
                    //await containerReference.SetPermissionsAsync(new BlobContainerPermissions
                    //{
                    //    PublicAccess = BlobContainerPublicAccessType.Blob
                    //});
                    await blockBlobRef.UploadFromStreamAsync(contentStream);
                }
            }
            catch (Exception ex)
            {
                //Error here
            }
        }
    }
}