VB.NET

Azure Storage: Download Blob to File

See more Azure Cloud Storage Examples

Sample code to download an Azure blob to a file. VB.NET

Dim success As Boolean = False

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim rest As New Chilkat.Rest

' Connect to the Azure Storage Blob Service
Dim bTls As Boolean = True
Dim port As Integer = 443
Dim bAutoReconnect As Boolean = True
' In this example, the storage account name is "chilkat".
success = rest.Connect("chilkat.blob.core.windows.net",port,bTls,bAutoReconnect)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' Provide Azure Cloud credentials for the REST call.
Dim azAuth As New Chilkat.AuthAzureStorage
azAuth.AccessKey = "AZURE_ACCESS_KEY"
' The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.Account = "chilkat"
azAuth.Scheme = "SharedKey"
azAuth.Service = "Blob"
' This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.XMsVersion = "2021-08-06"
success = rest.SetAuthAzureStorage(azAuth)

' Note: The application does not need to explicitly set the following
' headers: Content-Length, x-ms-date, Authorization.  These headers
' are automatically set by Chilkat.

' Setup a file stream for the download
Dim fileStream As New Chilkat.Stream
fileStream.SinkFile = "C:/temp/qa_output/starfish.jpg"

' Indicate that the call to FullRequestNoBody should send the response body
' to fileStream if the response status code is 200.
' If a non-success response status code is received, then nothing
' is streamed to the output file and the error response is returned by FullRequestNoBody.
Dim expectedStatus As Integer = 200
rest.SetResponseBodyStream(expectedStatus,True,fileStream)

' The Azure blob container is "test", the file is "starfish.jpg"
Dim responseStr As String = rest.FullRequestNoBody("GET","/test/starfish.jpg")
If (rest.LastMethodSuccess <> True) Then

    ' Examine the request/response to see what happened.
    Debug.WriteLine("response status code = " & rest.ResponseStatusCode)
    Debug.WriteLine("response status text = " & rest.ResponseStatusText)
    Debug.WriteLine("response header: " & rest.ResponseHeader)
    Debug.WriteLine("response body (if any): " & responseStr)
    Debug.WriteLine("---")
    Debug.WriteLine("LastRequestStartLine: " & rest.LastRequestStartLine)
    Debug.WriteLine("LastRequestHeader: " & rest.LastRequestHeader)
    Exit Sub
End If


Debug.WriteLine("Success.")