FileUpload file to Azure Blob Storage - asp.net

Question

I have a System.Web.UI.WebControls.FileUpload control that passes both Word and PDF files that need to be stored in Azure Blob Storage.
From the Code Behind page it passes to the common library to manage Azure Functions:
Private Sub UploadButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles UploadButton.Click
Dim fileExt As String = String.Empty
Dim newGuid As New Guid
Dim fileName As String
Dim documentType As Document.DocumentType
Page.Validate()
newGuid = Guid.NewGuid
If Page.IsValid() AndAlso Me.FileUploadNewDoc.HasFile Then
Try
'Test that MIME is either msword of pdf
If FileUploadNewDoc.PostedFile.ContentType.Contains("msword") Then
fileExt = "doc"
documentType = Document.DocumentType.LeaseWordDoc
ElseIf FileUploadNewDoc.PostedFile.ContentType.Contains("pdf") Then
fileExt = "pdf"
documentType = Document.DocumentType.LeasePDF
Else
fileExt = "na"
End If
If fileExt <> "na" Then
fileName = newGuid.ToString & "." & fileExt
AzureStorage.SaveBlob(FileUploadNewDoc.FileContent, fileName, mDocumentContainer, mStorageConnectionString)
End If
Catch ex As Exception
' Handle Error
Finally
FileUploadNewDoc.Dispose()
End Try
End If
End Sub
The AzureStorage.SaveBlob code:
Public Function SaveBlob(ByRef fileContent As Stream,
ByVal fileName As String,
ByVal containerName As String,
ByVal storageConnectionString As String) As Boolean
Dim storageAccount As CloudStorageAccount = CloudStorageAccount.Parse(storageConnectionString)
Dim blobClient As CloudBlobClient = storageAccount.CreateCloudBlobClient()
Dim container As CloudBlobContainer = blobClient.GetContainerReference(containerName)
Dim blockBlob As CloudBlockBlob = container.GetBlockBlobReference(fileName)
Using fileContent
fileContent.Position = 0
blockBlob.UploadFromStream(fileContent)
End Using
Return True
End Function
My questions:
Is this best way to take the File that has been uploaded and save it to Azure Blob Storage?
Am I handling the Stream correctly? I'm passing ByRef and have a Using statement around the usage.
Should I be setting content type explicitly when saving it to storage? If so how do I do that?
Note, I normally code in C# so an example in C# is fine if you're not familiar with VB.NET.

Answer 1

Is this best way to take the File that has been uploaded and save it
to Azure Blog Storage?
The best way depends on your use case. If it is just small files you're OK. If you want to support large files you might want to do chunked uploading. You can take blocks of 1 megabyte which you can upload separately or in parallel. Once you are done uploading all the blocks you commit the file and it is stiched together in Azure Blob storage. Look at CloudBlockBlob.PutBlock and CloudBlockBlob.PutBlockList.
Am I handling the Stream correctly? I'm passing ByRef and have a Using
statement around the usage.
You are but if you want to support larger files you might want to upload with JavaScript and create two endpoint to receive chunks and to commit after all chunks are sent. There are multiple libraries that can help you.
Should I be setting content type explicitly when saving it to storage? If so
how do I do that?
If you upload files that you want to embed in HTML it's wise to have a content type. If you want the links to the file to be download links you don't have to. Although it can never hurt.
blockBlob.Properties.ContentType = "image/jpeg";