Comma-separated listbox

Question

I have a Listbox with horizontal orientation and I need the Textblock values to be separated by commas.

I've reached this solution:

    <DataTemplate x:Key="toStringDataTemplate">
        <TextBlock  Margin="2,0,0,0"  TextWrapping="Wrap">
            <Run Text="{Binding name}"/>
            <Run Text=","/>
        </TextBlock>
    </DataTemplate>

But this outputs trailing commas: value1,value2,value3,

I need the last comma to be collapsed if its the last item in the Observable Collection.

Any help would be appreciated.