c#文件操作

创建新文件,并添加内容

System.IO.File.WriteAllBytes

System.IO.File.WriteAllText

常用的读写文件

新建一个Log.txt文件
引入System.IO名称空间,用文件流
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace StreamWrite
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                FileStream aFile = new FileStream("Log.txt", FileMode.OpenOrCreate);
                StreamWriter sw = new StreamWriter(aFile);

                bool truth = true;
                // Write data to file.
                sw.WriteLine("Hello to you.");
                sw.WriteLine("It is now {0} and things are looking good.",
                    DateTime.Now.ToLongDateString());
                sw.Write("More than that,");
                sw.Write(" it's {0} that C# is fun.", truth);
                sw.Close();
            }
            catch (IOException ex)
            {
                Console.WriteLine("An IOException has been thrown!");
                Console.WriteLine(ex.ToString());
                Console.ReadLine();
                return;
            }
        }
    }
}

读取文件，这里介绍StreamReader对象
static void Main(string[] args)
{
     string strLine;
     try
     {
            FileStream aFile = new FileStream("Log.txt",FileMode.Open);
            StreamReader sr = new StreamReader(aFile);
            strLine = sr.ReadLine();
            //Read data in line by line
      while(strLine != null)
            {
                Console.WriteLine(strLine);
                Line = sr.ReadLine();
             }
            sr.Close();
       }catch (IOException ex)
            {
                Console.WriteLine("An IOException has been thrown!");
                Console.WriteLine(ex.ToString());
                Console.ReadLine();
                return;
            }
}
另外对于简单的文档可以直接sr.ReadToEnd()从头读到尾,还有sr.Read() 返回类型char

FileStream aFile = new FileStream("D:\\Log.txt", FileMode.Append, FileAccess.Write);//FileMode.Append, FileAccess.Write设置追加还是覆盖等
            StreamWriter sw = new StreamWriter(aFile);

最简单的日志记录

    public class Log
    {
        public static void WriteToLog(string str)
        {
            try
            {
                lock (typeof(Log))
                {
                    FileStream aFile = new FileStream("D:\\Log.txt", FileMode.Append);
                    StreamWriter sw = new StreamWriter(aFile);
                    sw.WriteLine(str);
                    sw.Close();
                }
            }
            catch { }
        }
    }