Input not in the correct format error in WPF

[Ganesh Gebhard]

I want to use your class in my WPF C# program, but I keep encounter the same problem over and over again with sending new values to the PLC.

First, I duplicated every step you took in your client example for sending the data: Empty listbox, a button to add numbers to the listbox and a button to send it. This works just fine.

Now I changed the listbox in such a way that it is not empty anymore: I hard-coded a item in it with the value of 5.
No I'm getting the error 'Input value was not in the correct format'.

The WPF code:

<ListBox x:Name="lbTest" HorizontalAlignment="Left" Height="296" Grid.RowSpan="2" VerticalAlignment="Top" Width="100" Margin="382,10,0,0">
            <ListBoxItem Content="5"/>
        </ListBox>

De rest is exactly the same.

Do you know what's wrong here?

Ganesh