C# 写CSV文件字符串前面0不显示的解决办法

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace CsvTest

{

    class Program

    {

        static void Main(string[] args)

        {

            FileStream fs = File.OpenWrite("D:\\test.csv");

            StreamWriter sw = new StreamWriter(fs);

            sw.WriteLine(((char)(9)).ToString()  +"012345");

            sw.Close();

        }

    }

}