using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.IO;namespace file_Operations{    class Program    {        static void Main(string[] args)        {            FileStream fs = null;            StreamWriter writer = null;            //文件路径            string path = "D:\\test.txt";            //判断路径下文件是否存在            if (!File.Exists(path))            {                fs = File.Create(path);                Console.WriteLine("新建一个文件:{0}",path);            }            else            {                fs = File.Open(path,FileMode.Open);                Console.WriteLine("文件已存在直接打开");            }            //初始化对象            writer = new StreamWriter(fs);            writer.Write("test文本");            Console.WriteLine("向文本中写入数据");            //关闭缓存            writer.Flush();            writer.Close();            fs.Close();            Console.WriteLine("关闭数据流");        }    }}