How to use Delegates and Events in VB

Updater.vb

Imports System.Data.SqlClient

Module Updater

	Sub Main()
		Console.WriteLine("Welcome to the cool async updater")

		dim updater = New DatabaseUpdater(new UpdateScanner())
		addHandler updater.ErrorRaised, AddressOf InformUserOfError
		AddHandler Updater.Success, AddressOf InformUserOfSuccess

		dim updaterRun = Task.Factory.StartNew(Async Sub() Await updater.Run())
		updaterRun.Wait()

		Console.ReadKey()
	End Sub

	Private Sub InformUserOfSuccess(eventdetails As ExecutionResult)
		Dim color = console.BackgroundColor		

		If eventdetails.Success then
			Console.ForegroundColor = ConsoleColor.Green

			Console.WriteLine("You did it! Teh Updates ran")
			Console.WriteLine(eventdetails.Message)			
		Else 
			Console.ForegroundColor = ConsoleColor.Yellow

			Console.WriteLine("Oh man there were problems")
			Console.WriteLine(eventdetails.Message)
		End If

		Console.ForegroundColor = color
	End Sub

	Private Sub InformUserOfError(eventdetails As ExecutionResult)
		dim color = console.ForegroundColor
		Console.ForegroundColor = ConsoleColor.Red

		Console.WriteLine("{0}, {1}", eventdetails.Message, eventdetails.Exception.Message)

		Console.ForegroundColor = color
	End Sub
End Module

public delegate sub SuccessEvent(eventDetails As ExecutionResult)
Public Delegate Sub ErrorEvent(eventDetails as ExecutionREsult)

Public Class DatabaseUpdater
	public Event Success as SuccessEvent
	public Event ErrorRaised as ErrorEvent

	Private ReadOnly _updateScanner As IUpdateScanner

	public Sub New (updateScanner As IUpdateScanner)
		Me._updateScanner = updateScanner
	end Sub 

	public Async function Run() As Task
		Dim updates = Me._updateScanner.Updates().ToArray()		
		dim failed as Integer

		If updates.Any() then
			try
				Using conn as New SqlConnection("")
					await conn.OpenAsync()

					for each u in updates
						dim result = Await Update(u, conn)

						If result = false
							failed = failed + 1
						End If
					Next

					conn.Close()
				End Using
			Catch ex As Exception
				RaiseEvent ErrorRaised(New ExecutionResult(false, "Unable to create the connection", ex))

				return
			End Try

		End If

		RaiseEvent Success(new ExecutionResult(failed = 0, $"{updates.Count() - failed} of {updates.Count()} Updates completed successfully", nothing))
	End function

	 Async Function Update(updateCommand As string, conn As SqlConnection) as Task(Of boolean)
		Try
			Using command As New SqlCommand(updateCommand, conn)
				command.CommandType = CommandType.Text

				Await command.ExecuteNonQueryAsync()
			End Using
		Catch ex As Exception
			RaiseEvent ErrorRaised(new ExecutionResult(False, $"There was an error running the update `{updateCommand}`", ex))

			return false
		End Try

		return true
	End Function
End Class

Public Class ExecutionResult
	Property Success() As boolean
	Property Message() As string
	Property Exception() As Exception

	Public sub New(success As Boolean, message As String, exception As Exception)
		me.Success = success
		me.Message = message
		me.Exception = exception
	End sub
End Class

public Interface IUpdateScanner
	function Updates() As IEnumerable(of string) 
End Interface

Public Class UpdateScanner 
	Implements IUpdateScanner

	Public Function Updates() As IEnumerable(Of String) Implements IUpdateScanner.Updates
		Dim list  = New List(Of String)()
		list.Add("CREATE TABLE [dbo].[Pet](
	[Type] [int] NULL
) ON [PRIMARY]")
		list.Add("CREATE TABLE [dbo].[Pie](
	[Type] [int] NULL
) ON [PRIMARY]")
		Return list
	End Function
End Class