类的构造函数 this 关键字

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Bundle b = new Bundle("1", "2");
        }
    }
    public class Bundle
    {
        protected Bundle()
        {

        }

        public Bundle(string virtualPath, string cdnPath)
            : this(virtualPath, cdnPath, null)
        {
            Console.Write(12);
        }


        public Bundle(string virtualPath, string cdnPath, object obj)
        {
            Console.Write(123);
        }
    }
}