Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        Me.RichTextBox1.Text = "Dies ist mein Text, der selektiert werden kann."
    End Sub
 
    Private Sub RichTextBox1_SelectionChanged(ByVal sender As Object, ByVal e _
      As System.EventArgs) Handles RichTextBox1.SelectionChanged
        If Me.RichTextBox1.SelectionFont Is Nothing Then
            Me.Text = "Der Text enthält verschiedene Fontgrößen."
        Else
            Me.Text = "Fontgröße: " & _
              Me.RichTextBox1.SelectionFont.Size.ToString
        End If
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Me.RichTextBox1.SelectionStart = 10
        Me.RichTextBox1.SelectionLength = 5
        Me.RichTextBox1.SelectionFont = New Font("Arial", 20, FontStyle.Regular)
    End Sub
End Class