Request.Content.ReadAsMultipartAsync Throws System.IO exception - azure

Question

I am uploading an image to an ASP WebAPI service and then uploading it to windows azure. everything was working great but suddenly I started getting the following exception:
System.IO.IOException: The process cannot access the file
'C:\DWASFiles\Sites\Tasteat\Temp\BodyPart_a5c79910-6077-4c24-b814-10fdc0e0b3d4'
because it is being used by another process.
This is the code that throws the exception:
var provider = new BlobStorageProvider(container);
Trace.TraceInformation("Uploading raw image to blob");
await Request.Content.ReadAsMultipartAsync(provider);
Trace.TraceInformation("Uploading finished");
I know its this line await Request.Content.ReadAsMultipartAsync(provider); because I see the line before it in the log but not the line after it.
Any ideas?
Everything was working great up until a few days

Answer 1

So as it seems the code I posted above actually saves a local file and only then uploaded it to the server, which causes the error but also is slow.
after a lot of trying I finally change to the following solution and everything started working and it was even faster!
first create a streamprovider:
public class BlobStorageMultipartStreamProvider : MultipartStreamProvider
{
private readonly string _containerName;
private readonly string _fileName;
public BlobStorageMultipartStreamProvider(string containerName, string fileName)
{
_containerName = containerName;
_fileName = fileName;
}
public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
{
Stream stream = null;
if (!String.IsNullOrWhiteSpace(_fileName))
{
string connectionString = ConfigurationManager.ConnectionStrings["BlobStorage"].ConnectionString;
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer blobContainer = blobClient.GetContainerReference(_containerName);
CloudBlockBlob blob = blobContainer.GetBlockBlobReference(_fileName);
stream = blob.OpenWrite();
}
return stream;
}
}
The upload code:
string fileName = Guid.NewGuid()+".Png";
MultipartStreamProvider provider = new BlobStorageMultipartStreamProvider("container",fileName);
Trace.TraceInformation("Uploading raw image to blob");
await Request.Content.ReadAsMultipartAsync(provider);
Trace.TraceInformation("Uploading finished");