How to show a progress bar while uploading data to azure blob in Windows store app

Question

I have followed the following post to do the upload in chunks to blob

How to track progress of async file upload to azure storage

But this is not working in windows store app or windows 8.1 app as there is no support for MemoryStream in win 8.1 app.

Anyhow I have modified the code in the above thread and come up with something like the following

        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.");
            });
        }
    }

The above code will save the file in blob and the progress is also fine but the saved file in blob is always in 0 bytes . After debugging I found there was an error thrown after var ado = myBlob.PutBlockAsync(blockId, fs.AsRandomAccessStream(), null).AsTask(); for the last blob transfer as

<?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>

Then on the last commit the error thrown after myBlob.PutBlockListAsync(blockIds) as The specified block list is invalid

So please someone help me to to figure out where I am doing wrong or what is the possible solution to make it work 100%.

Answer 1

Use AsTask() like this.

 CancellationTokenSource _cts;

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

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