Azure 存储：BlobClient 在上传大文件时不断重置自身

如何解决Azure 存储：BlobClient 在上传大文件时不断重置自身

我正在尝试从连接到快速 Wifi 连接的手机上传 200 MB 的视频文件。我正在使用适用于 .NET 的 Azure 存储 SDK v12，但以下代码在大约 30% 的上传进度后不断自我重置。发生重置时，进度从0开始，不会抛出异常。

await blobClient.UploadAsync(stream,progressHandler: new Progress<long>(progress =>
{
     // show progress bar
}),cancellationToken: cancellationToken);

v12 支持上传大文件吗？如果我没记错的话，旧的 API 能够上传单个块。我的印象是上述上传方法会隐式处理分块。

如何使用最新的 sdk 上传大文件？

附言我尝试以非常高的并发性和 1 MB 的传输大小传递 StorageTransferOptions，但没有任何区别。

编辑：等了很长时间后，我能够抛出异常。我看到多个任务被取消，因为

Cannot access a disposed object.
Object name: 'MobileAuthenticatedStream'.

  at Mono.Net.Security.MobileAuthenticatedStream.StartOperation (Mono.Net.Security.MobileAuthenticatedStream+OperationType type,Mono.Net.Security.AsyncProtocolRequest asyncRequest,System.Threading.CancellationToken cancellationToken) [0x00245] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/System/Mono.Net.Security/MobileAuthenticatedStream.cs:410 
  at System.Net.Http.HttpConnection.WriteAsync (System.ReadOnlyMemory`1[T] source) [0x00118] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnection.cs:1008 
  at System.IO.Stream.CopyToAsyncInternal (System.IO.Stream destination,System.Int32 bufferSize,System.Threading.CancellationToken cancellationToken) [0x000e7] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corert/src/System.Private.CoreLib/shared/System/IO/Stream.cs:152 
  at Azure.Core.RequestContent+StreamContent.WriteToAsync (System.IO.Stream stream,System.Threading.CancellationToken cancellation) [0x00094] in <7b1dc95b0b4841539beb48023c1128d3>:0 
  at Azure.Core.Pipeline.HttpClientTransport+PipelineRequest+PipelineContentAdapter.SerializeToStreamAsync (System.IO.Stream stream,System.Net.TransportContext context) [0x0007c] in <7b1dc95b0b4841539beb48023c1128d3>:0 
  at System.Net.Http.HttpContent.CopyToAsyncCore (System.Threading.Tasks.ValueTask copyTask) [0x00022] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/HttpContent.cs:361 

所以 blobClient 中似乎内置了并行化，但它仍然失败。此外，我无法使用 https://www.nuget.org/packages/Microsoft.Azure.Storage.DataMovement，因为它不适用于 Xamarin Forms。

解决方法

如果要分块上传文件到Azure blob存储，请参考以下代码

public async Task upload(Stream stream){
            string connectionString = "";
            string containerName = "upload";
            string blobName = "";
            BlockBlobClient blobClient = new BlockBlobClient(connectionString,containerName,blobName);
           
            List<string> blockList = new List<string>();

                while (true) {
                    byte[] b = new byte[1024 * 1024];
                    var n = await stream.ReadAsync(b,1024 * 1024);
                    if (n == 0) break;
                    string blockId = Guid.NewGuid().ToString();
                    string base64BlockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(blockId));
                    await blobClient.StageBlockAsync(base64BlockId,new MemoryStream(b,true));
                    blockList.Add(base64BlockId);
                }

                await blobClient.CommitBlockListAsync(blockList);

   
}

---

更新

如果要使用sas token，请参考以下代码

var uri = new Uri($"https://{storageAccountName}.blob.core.windows.net/{containerName}/{blobName}?{sasToken}");
BlockBlobClient blobClient = new BlockBlobClient(uri);

,

v12 同时具有 BlobClient 和 BlockBlobClient。就是BlockBlobClient，具有分块和上传块的功能。

你可以试试 Microsoft.Azure.Storage.DataMovement https://www.nuget.org/packages/Microsoft.Azure.Storage.DataMovement

"Microsoft Azure Storage DataMovement Library 提供了一组 API 扩展现有的 Azure Storage .Net 客户端库以帮助 客户传输具有高性能的 Azure Blob 和文件存储， 可扩展性和可靠性。”