VB Net: How to call this Public Shared Function? - vb.net

Question

Can anybody help me with a couple of doubts?
How can I call this Public Shared Function from a button? and how can I show "result" (list of files) in a datagridview?
Thanks.
Imports System.Threading
Imports System.Threading.Tasks
Imports Google.Apis.Auth.OAuth2
Imports Google.Apis.Drive.v2
Imports Google.Apis.Drive.v2.Data
Imports Google.Apis.Services
Imports System.Net
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
'?
End Sub
Public Shared Function retrieveAllFiles(service As DriveService) As List(Of File)
Dim Secrets = New ClientSecrets()
Secrets.ClientId = "CLIENT ID"
Secrets.ClientSecret = "CLIENT SECRET"
Dim scope = New List(Of String)
scope.Add(DriveService.Scope.Drive)
Dim credential = GoogleWebAuthorizationBroker.AuthorizeAsync(Secrets, scope, "USER", CancellationToken.None).Result()
Dim initializer = New BaseClientService.Initializer
initializer.HttpClientInitializer = credential
initializer.ApplicationName = "APPLICATION NAME"
Dim service = New DriveService(initializer)
Dim request As FilesResource.ListRequest = service.Files.List()
Dim result As New List(Of File)()
Dim request As FilesResource.ListRequest = service.Files.List()
Do
Try
Dim files As FileList = request.Execute()
result.AddRange(files.Items)
request.PageToken = files.NextPageToken
Catch e As Exception
Console.WriteLine("An error occurred: " + e.Message)
request.PageToken = Nothing
End Try
Loop While Not [String].IsNullOrEmpty(request.PageToken)
Return result
End Function
End Class

Answer 1

If it's in the same class, you can just call it by name, same as a non-shared function:
lst = retrieveAllFiles(service)
If it's in another class, you need to prefix it with class name:
lst = className.retrieveAllFiles(service)
Official reference:
Shared Members in Visual Basic