Imports System.Threading

Public Class frmThreadUI

    Inherits System.Windows.Forms.Form

    Private Sub LoadCustomers()

        ' this function will execute on a separate thread.

        Dim dsCustomers As CustomerSet = Customer.GetAll()

        ' call our threadsafe DisplayCustomers from our separate thread

        DisplayCustomers_ThreadSafe(dsCustomers)

    End Sub

    Private Sub DisplayCustomers_ThreadSafe(ByVal dsCustomers As CustomerSet)

        ' this is a threadsafe method called from the separate worker thread

        Dim oDel As New DisplayCustomersDelegate(AddressOf Me.DisplayCustomers)

        Dim args() As DataSet = {dsCustomers}

        Me.Invoke(oDel, args)

    End Sub

    ' define a delegate (signature) for the callback.

    Delegate Sub DisplayCustomersDelegate(ByVal dsCustomers As CustomerSet)

    Private Sub DisplayCustomers(ByVal dsCustomers As CustomerSet)

        ' display the customer list in the ListBox

        lstCustomers.DataSource = dsCustomers.Tables(0)

        lstCustomers.DisplayMember = "CompanyName"

        lstCustomers.ValueMember = "CustomerId"

    End Sub

    Private Sub frmThreadUI_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load

        ' give a "loading" message.

        lstCustomers.Items.Add("Loading... please wait.")

        ' kick off a separate thread to load the Customers into a ListBox

        Dim oTS As New ThreadStart(AddressOf LoadCustomers)

        Dim oThread As Thread = New Thread(oTS)

        oThread.Start()

    End Sub

End Class