string.join 给字符串添加分隔符！！

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _03StringJoin
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = "ABCDEFGHIJK";
            str = StrLink(str, "-");
            Console.WriteLine(str);
            Console.ReadKey();

        }


        static string StrLink(string str,string split)
        {
            char[] chArr = str.ToCharArray();            

            return String.Join(split, chArr); 
        }

    }
}