Dim sb As New StringBuilder()
 
For i = 1 To RichTextBox1.TextLength
    sb.Append(String.Format("{0:X2}", Hex(i)))
Next
Zwischentext = sb.ToString()
 
Using fs As New FileStream(AusgabeDatei, FileMode.Create, FileAccess.Write)
    Using writer As New BinaryWriter(fs)
        For i = 0 To Zwischentext.Length \ 2 - 1
            Dim b As Byte = Byte.Parese( _
                Zwischentext.Substring(i * 2, 2), _
                Globalization.NumberStyles.HexNumber)
            writer.Write(b)
        Next
        writer.Close()
    End Using
End Using

Using fs As New FileStream(AusgabeDatei, FileMode.Create, FileAccess.Write)
    Using writer As New BinaryWriter(fs)
        writer.Write(Hex)
        writer.Close()
    End Using
End Using