Google Drive API v3 VB.NET Upload and Download Files to ServiceAccount - vb.net

Question

I've been trying to follow https://developers.google.com/drive/v3/web/quickstart/dotnet and the Google API documentation, as well as searching all over the internet, but there really isn't a straightforward example to use (especially for v3)
I have a VB.NET GUI that contains a listview with the names of all plain text files in a folder. Clicking on one will display its' contents in a textbox. You can also type into a blank text box and save it. I want to allow multiple users to upload their text file to the Google Drive and be able to download all text files that are stored there.
I don't have much of an issue translating code from C# to VB.NET, and I think I'm fine with authenticating the service account with Google (or at least I don't get an error), but uploading only shows me response = Nothing. Any help is appreciated.
I created the service account through Google and have the following:
Dim service = AuthenticateServiceAccount("xxxxx#xxxxx.iam.gserviceaccount.com", "C:\Users\xxxxx\Documents\Visual Studio 2015\Projects\MyProject\accountkey-0c1aa839896b.json")
If drive.UploadFile(service, "C:\Users\xxxxx\Documents\Visual Studio 2015\Projects\MyProject\file.txt") Is Nothing Then
MsgBox("File not uploaded")
Else
MsgBox("File uploaded")
End If
Authenticate:
Public Function AuthenticateServiceAccount(ByVal serviceAccountEmail As String, ByVal serviceAccountCredentialFilePath As String) As DriveService
Dim scopes As String() = {DriveService.Scope.Drive, DriveService.Scope.DriveAppdata, DriveService.Scope.DriveReadonly, DriveService.Scope.DriveFile, DriveService.Scope.DriveMetadataReadonly, DriveService.Scope.DriveReadonly, DriveService.Scope.DriveScripts}
Try
If (String.IsNullOrEmpty(serviceAccountCredentialFilePath)) Then
Throw New Exception("Path to the service account credentials file is required.")
End If
If Not IO.File.Exists(serviceAccountCredentialFilePath) Then
Throw New Exception("The service account credentials file does not exist at: " + serviceAccountCredentialFilePath)
End If
If (String.IsNullOrEmpty(serviceAccountEmail)) Then
Throw New Exception("ServiceAccountEmail is required.")
End If
If (Path.GetExtension(serviceAccountCredentialFilePath).ToLower() = ".json") Then
Dim credential As GoogleCredential
Dim sstream As New FileStream(serviceAccountCredentialFilePath, FileMode.Open, FileAccess.Read)
credential = GoogleCredential.FromStream(sstream)
credential.CreateScoped(scopes)
'Create the Analytics service.
Return New DriveService(New BaseClientService.Initializer() With {
.HttpClientInitializer = credential,
.ApplicationName = "Drive Service Account Authentication Sample"
})
Else
Throw New Exception("Unsupported Service accounts credentials.")
End If
Catch e As Exception
MsgBox("Create service account DriveService failed" + e.Message)
Throw New Exception("CreateServiceAccountDriveFailed", e)
End Try
End Function
Upload File:
Public Function UploadFile(service As DriveService, FilePath As String) As Google.Apis.Drive.v3.Data.File
If (System.IO.File.Exists(FilePath)) Then
Dim body As New Google.Apis.Drive.v3.Data.File()
body.Name = System.IO.Path.GetFileName(FilePath)
body.Description = "Text file"
body.MimeType = "text/plain"
'files content
Dim byteArray As Byte() = System.IO.File.ReadAllBytes(FilePath)
Dim stream As New System.IO.MemoryStream(byteArray)
Try
Dim request As FilesResource.CreateMediaUpload = service.Files.Create(body, stream, "text/plain")
request.Upload()
Return request.ResponseBody
Catch e As Exception
MsgBox("An error occurred: " + e.Message)
Return Nothing
End Try
Else
MsgBox("File does not exist: " + FilePath)
Return Nothing
End If
End Function

Answer 1

As stated here, since you are using a Service Account, all the folders and files will be created in this Service Account's Drive which cannot be accessed through a web UI and will be limited to the default quota.
To add content in a user's Drive, you will need to go through the regular OAuth 2.0 flow to retrieve credentials from this user. You can find more information about OAuth 2.0 on this pages:
Retrieve and use OAuth 2.0 credentials.
Quickstart: it has a quickstart sample in C# that you could use.
Using OAuth 2.0 to access Google APIs
You may also check this related thread: upload files to Google drive in VB.NET - searching for working code