Public Class frmRTFTest
 
    Dim sp As New SplitContainer With {.Parent = Me, .Dock = DockStyle.Fill}
    Dim grp1, grp2 As New GroupBox
 
    Dim rtf1 As New RichTextBox With {.Parent = grp1, .Dock = DockStyle.Fill}
    Dim rtf2 As New RichTextBox With {.Parent = grp2, .Dock = DockStyle.Fill}
 
 
    Private Sub frmRTFTest_Load(sender As System.Object, _
         e As System.EventArgs) Handles MyBase.Load
 
 
        sp.Panel1.Controls.Add(grp1)
        sp.Panel2.Controls.Add(grp2)
 
        Dim dt As New DataTable
        dt.Columns.Add("SP1")
        dt.Columns.Add("SP2")
 
        With rtf1
            .Text = "Das ist der Text in der ersten Richtextbox"
            .SelectionStart = 12
            .SelectionLength = 5
            .SelectionFont = _
            New Font("Arial", 12, FontStyle.Strikeout)
            .SelectionColor = Color.Red
            .SelectionLength = 0
        End With
 
        With rtf2
            .Text = "Das ist der Text in der zweiten Richtextbox"
            .SelectionStart = 12
            .SelectionLength = 5
            .SelectionFont = _
             New Font("Letter", 16, FontStyle.Bold Or FontStyle.Underline)
            .SelectionColor = Color.Green
        End With
 
        dt.Rows.Add(rtf1.Rtf.ToString, rtf2.Rtf.ToString)
        rtf1.Clear() : rtf2.Clear()
 
        Dim bs As New BindingSource(dt, Nothing)
 
        rtf1.DataBindings.Add("RTF", bs, "SP1")
        rtf2.DataBindings.Add("RTF", bs, "SP2")
 
    End Sub
End Class