接受 用户输入直 并转换字符 输出！

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

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            string username;
            username = Console.ReadLine();
            Console.WriteLine("welcome {0}!",username);
            Console.ReadKey();
        }
    }
}