如何在 Windows 商店应用程序中将数据上传到 azure blob 时显示进度条

Question

我按照下面的帖子分块上传到blob

How to track progress of async file upload to azure storage

但这不适用于 windows 商店应用程序或 windows 8.1 应用程序，因为在 win 8.1 应用程序中不支持 MemoryStream。

无论如何我已经修改了上面线程中的代码并提出了类似以下的内容

        CloudBlobClient myBlobClient = storageAccount.CreateCloudBlobClient();
        var filePicker = new FileOpenPicker();

        filePicker.FileTypeFilter.Add("*");
        var file = await filePicker.PickSingleFileAsync();
        string output = string.Empty;

            var fileName = file.Name;


        myBlobClient.SingleBlobUploadThresholdInBytes = 1024 * 1024;
        CloudBlobContainer container = myBlobClient.GetContainerReference("files");
        //container.CreateIfNotExists();
        CloudBlockBlob myBlob = container.GetBlockBlobReference(fileName);
        var blockSize = 256 * 1024;
        myBlob.StreamWriteSizeInBytes = blockSize;

        var fileProp = await file.GetBasicPropertiesAsync();
        var bytesToUpload = fileProp.Size;
        var fileSize = bytesToUpload;



        if (bytesToUpload < Convert.ToUInt64(blockSize))
        {
            CancellationToken ca = new CancellationToken();
            var ado = myBlob.UploadFromFileAsync(file).AsTask();
            await
                            //Console.WriteLine(ado.Status); //Does Not Help Much
                            ado.ContinueWith(t =>
                            {
                                //Console.WriteLine("Status = " + t.Status);
                                //Console.WriteLine("It is over"); //this is working OK
                            });
        }
        else
        {
            List<string> blockIds = new List<string>();
            int index = 1;
            ulong startPosition = 0;
            ulong bytesUploaded = 0;
            do
            {
                var bytesToRead = Math.Min(Convert.ToUInt64(blockSize), bytesToUpload);
                var blobContents = new byte[bytesToRead];




                using (Stream fs = await file.OpenStreamForWriteAsync())
                {
                    fs.Position = Convert.ToInt64(startPosition);
                    fs.Read(blobContents, 0, (int)bytesToRead);
                    //var iStream = fs.AsInputStream();



                    ManualResetEvent mre = new ManualResetEvent(false);
                    var blockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(index.ToString("d6")));
                    //Console.WriteLine("Now uploading block # " + index.ToString("d6"));
                    blockIds.Add(blockId);
                    var ado = myBlob.PutBlockAsync(blockId, fs.AsRandomAccessStream(), null).AsTask();
                    await ado.ContinueWith(t =>
                              {
                                  bytesUploaded += bytesToRead;
                                  bytesToUpload -= bytesToRead;
                                  startPosition += bytesToRead;
                                  index++;
                                  double percentComplete = (double)bytesUploaded / (double)fileSize;
                                  output += (percentComplete * 100).ToString() + ",";
                        // AppModel.TasksFormObj.SetProgress(percentComplete * 100);
                        // Console.WriteLine("Percent complete = " + percentComplete.ToString("P"));
                        mre.Set();
                              });

                mre.WaitOne();
                }
            }
            while (bytesToUpload > 0);
            //Console.WriteLine("Now committing block list");
            var pbl = myBlob.PutBlockListAsync(blockIds).AsTask();
             pbl.ContinueWith(t =>
            {
                //Console.WriteLine("Blob uploaded completely.");
            });
        }
    }

上面的代码会将文件保存在blob中，进度也很好，但是blob中保存的文件总是0字节。调试后发现 var ado = myBlob.PutBlockAsync(blockId, fs.AsRandomAccessStream(), null).AsTask(); 后抛出错误最后一个 blob 传输为

<?xml version="1.0" encoding="utf-16"?>
<!--An exception has occurred. For more information please deserialize this message via RequestResult.TranslateFromExceptionMessage.-->
<RequestResult>
  <HTTPStatusCode>400</HTTPStatusCode>
  <HttpStatusMessage>The value for one of the HTTP headers is not in the correct format.</HttpStatusMessage>
  <TargetLocation>Primary</TargetLocation>
  <ServiceRequestID>13633308-0001-0031-060b-7249ea000000</ServiceRequestID>
  <ContentMd5 />
  <Etag />
  <RequestDate>Sun, 28 Feb 2016 10:31:44 GMT</RequestDate>
  <StartTime>Sun, 28 Feb 2016 09:31:43 GMT</StartTime>
  <EndTime>Sun, 28 Feb 2016 09:31:44 GMT</EndTime>
  <Error>
    <Code>InvalidHeaderValue</Code>
    <Message>The value for one of the HTTP headers is not in the correct format.
RequestId:13633308-0001-0031-060b-7249ea000000
Time:2016-02-28T09:34:18.3545085Z</Message>
    <HeaderName>Content-Length</HeaderName>
    <HeaderValue>0</HeaderValue>
  </Error>
  <ExceptionInfo>
    <Type>StorageException</Type>
    <HResult>-2147467259</HResult>
    <Message>The value for one of the HTTP headers is not in the correct format.</Message>
    <Source>Microsoft.WindowsAzure.Storage</Source>
    <StackTrace>   at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.&lt;ExecuteAsyncInternal&gt;d__c`1.MoveNext()</StackTrace>
  </ExceptionInfo>
</RequestResult>

然后在最后一次提交时，myBlob.PutBlockListAsync(blockIds) 之后抛出的错误为 指定的阻止列表无效

所以请有人帮我找出我做错了什么，或者有什么可能的解决方案让它 100% 工作。

Answer 1

像这样使用AsTask()。

 CancellationTokenSource _cts;

 _cts = new CancellationTokenSource();//<--In Constructor 

 var progress = new Progress<double>(TranscodeProgress); 
 await var ado = myBlob.UploadFromFileAsync(file).AsTask(_cts.Token, progress);