Public Class frmWPFHost
 
    ' Create the WPF UserControl.
    Dim WithEvents tbc As New System.Windows.Controls.TextBox
    Dim host As New System.Windows.Forms.Integration.ElementHost()
    Dim WithEvents btnShowStartLine As New Button With {.Parent = Me, .Top = 2}
 
    Private Sub frmWPFHost_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
 
        host.Parent = Me
        host.Top = 50 : host.Height = 100 : host.Width = 300
 
        ' Assign the WPF UserControl to the ElementHost control's 
        ' Child property.
        host.Child = tbc
 
        'Demo-Text erstellen 
        Dim stb As New System.Text.StringBuilder(5000)
        For i As Integer = 0 To 200
            stb.AppendLine("Textzeile Nummer " & CStr(i + 2))
        Next i
 
        tbc.Text = "Ich bin eine Controls.Textbox-Instanz" & vbCrLf & _
          stb.ToString
        'Scrollbar anfordern
        tbc.VerticalScrollBarVisibility = _
        System.Windows.Controls.ScrollBarVisibility.Visible
 
        ' Add the ElementHost control to the form's collection of 
        ' child controls.
        Me.Controls.Add(host)
 
    End Sub
 
    Private Sub btnShowStartLine_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles btnShowStartLine.Click
 
        'Abfrage der ersten sichtbaren Zeile in der Textbox   
        MsgBox("Erste sichtbare Zeile: " & CStr(tbc.GetFirstVisibleLineIndex()))
 
    End Sub
End Class