Public Class frmInvokeDemo
 
 
    Dim tbo As New TextBox With _
      {.Parent = Me, .ReadOnly = True, .BackColor = Color.White}
 
    Delegate Sub stringDel(ByVal text As String)
 
 
 
    Private Sub frmInvokeDemo_Load(sender As System.Object, _
        e As System.EventArgs) Handles MyBase.Load
 
        Dim th As New Threading.Thread(AddressOf ShowLetters)
        th.Start()
    End Sub
 
 
    Private Sub ShowLetters()
 
        For i As Integer = 65 To 65 + 26
            ShowText(Microsoft.VisualBasic.Chr(i))
            Threading.Thread.Sleep(600)
        Next i
        ShowText("Thread ist beendet")
    End Sub
 
 
    Private Sub ShowText(ByVal text As String)
        ' Falls der Aufruf nicht aus dem UI-THread kommt, muß der
        ' Zugriff auf das Control per Invoke/Delegat erfolgen
 
        If tbo.InvokeRequired Then
            Dim d1 As New stringDel(AddressOf ShowText)
            Me.Invoke(d1, New Object() {text})    
        Else
            With tbo
                .Text = text
                .SelectionStart = .Text.Length
            End With
        End If
    End Sub
 
End Class