CsvConverter.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace MyCaffe.param.ui
{
    public class CsvConverter : TypeConverter
    {
        public override object ConvertTo(ITypeDescriptorContext context,
           CultureInfo culture, object value, Type destinationType)
        {
            List<String> v = value as List<String>;
 
            if (destinationType == typeof(string) && v != null)
            {
                return String.Join(",", v.ToArray());
            }
 
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }
}