C#中的文件流学习笔记第一篇

　　前言：这篇博客我主要说一下C#中文件流的使用规则，也是从最基础上面去说，也相信我们大家只要是干Web行业的这些知识点肯定能用上，其中介绍几个操作文件流的类，Path类，FileStream类，Read和Write方法的使用

Path

(1) 文件路径有什么特征？

1)[根目录:\]文件夹\文件名.后缀名

(2)合并路径 Combine

string p4 = Path.Combine(@"c:\123a\abc\", "白天不懂夜的黑.mp3");

string p5 = Path.Combine(@"c:\123a\abc", "白天不懂夜的黑.mp3");

(3)获得文件夹的路径 GetDirectoryName

string p2 = Path.GetDirectoryName(path);

(4)得到全路径 GetFullPath

string full = Path.GetFullPath("1.txt");

(5)得到后缀名 GetExtension

string p3 = Path.GetExtension(path);

(6)得到文件名 GetFileName

string p6 = Path.GetFileName(path);

(7)更改文件后缀名 ChangeExtension

string path = @"c:\HYL\CS\File\Exise.avi";

string p1= Path.ChangeExtension(path, "rmvb");

(8)返回临时文件夹 GetTempPath

string s= Path.GetTempPath();

2. FileStream(文件流),专门将文件以字节流的形式进行处理

(1)父类Stream(流)

(2)使用文件流，无非就是读取和写入文件

->读取文件，就必须想办法打开文件，使用构造方法

static void Main(string[] args)
 
{
 
                          using (FileStream fileRead = new FileStream(@"F:\heima\practice\总复习\文件流的读取\bin\Debug\SqlHelper.txt", FileMode.Open, FileAccess.Read))
 
         {
 
                    int num;
 
                    while ((num = fileRead.ReadByte()) != -1)
 
                    {
 
                            Console.Write((char)num);
 
                     }
 
                    Console.ReadKey();
 
        }
 
 }

(3)使用Writer创建文件并且写入信息：

static void Main(string[] args)
 
{
 
            using (FileStream fileWriter = new FileStream("file.txt", FileMode.Create, FileAccess.Write))
 
            {
 
                Console.WriteLine("请输入信息");
 
                string str = Console.ReadLine();
 
                byte[] bs = Encoding.Default.GetBytes(str);
 
                for (int i = 0; i < bs.Length; i++)
 
                {
 
                    fileWriter.WriteByte(bs[i]);
 
                }
 
            }
}

(4)自己手动书写一个ACSII码表，不需要百度了，只要我们程序员有计算机

static void Main(string[] args)
 
{
 
            List<string> list = new List<string>();
 
            list.Add("<body>");
 
            for (int i = 0; i < 128; i++)
 
            {
 
                list.Add(string.Format("子符  <font size=\"7\" color=\"red\">{0}</font>  的ASCII码为  <font size=\"7\" color=\"red\">{1}</font>  <br/>", (char)i, i));
 
            }
 
            list.Add("</body>");
 
            File.WriteAllLines("ASCII.html", list.ToArray(), Encoding.Default);
 
}

FileStream

　　　　(1) ReadByte() 读取一个字节，返回对应的直接表示数字的十进制形式

　　　　(2)WriteByte() 可以写一个字节

　　　　(3)复制文件，对文件加密,解密

static void Main(string[] args)
 
       {
 
           //对文件进行一个简单加密
 
           using (FileStream fileRead = new FileStream("梦想的力量.mp3", FileMode.Open, FileAccess.Read))
 
           {
 
               using (FileStream fileWrite = new FileStream("梦想.mp3", FileMode.Create, FileAccess.Write))
 
              {
 
                   int num = -1;
 
                   while ((num = fileRead.ReadByte()) != -1)
 
                   {
 
                       num++;
 
                       fileWrite.WriteByte((byte)num);
 
                  }
 
                   Console.WriteLine("OK");
 
               }
 
           }
 
           //对上面加密的文件进行解密
 
           using (FileStream fileRead = new FileStream("梦想.mp3", FileMode.Open, FileAccess.Read))
 
　　　　　{
 
               using (FileStream fileWrite = new FileStream("梦想_解密.mp3", FileMode.Create, FileAccess.Write))
 
               {
 
                   int num = -1;
 
                   while ((num = fileRead.ReadByte()) != -1)
 
                   {
 
                       num--;
 
                       fileWrite.WriteByte((byte)num);
 
                   }
 
                   Console.WriteLine("OK");
 
               }
 
           }
 
}

Read和Write的使用

(1) Read(存放数据的byte数组,从数组的第一号位置开始放数据，取出多少数据)

(2)一般情况使用的时候 Read(数组名,0,数组名.Length);

static void Main(string[] args)
 
{
 
            //读取文件流
 
            byte[] bs=new byte[10];
 
            using (FileStream fileRead = new FileStream("file.txt", FileMode.Open, FileAccess.Read))
 
            {
 
                //Read(存放数据的byte数组,从数组的第一号位置开始放数据，取出多少数据)
 
                //一般情况使用的时候 Read(数组名,0,数组名.Length);
 
                int count = 0;
 
                while ((count = fileRead.Read(bs, 0, bs.Length))>0)
 
                {
 
                    for (int i = 0; i < count; i++)
 
                    {
 
                        Console.WriteLine((char)bs[i]);
 
                    }
 
                }
 
            }
 
            //写流
 
            using(FileStream fileWrite=new FileStream("file.txt",FileMode.Create,FileAccess.Write))
 
            {
 
                byte[] bs = { 0, 97, 98, 99, 48, 49 };
 
                fileWrite.Write(bs, 1, bs.Length - 1);
 
            }
 
}

(3)使用Write和Read复制文件

1)语法实现

using(fileRead)

{

using(fileWrite)

{

byte[] bs=new byte[10*1024*1024];

int count=0;

while((count=fileRead.Read(bs,0,bs.Length))>0)

{

fileWrite.Write(bs,0,count);

}

使用命令行参数控制程序，实现控制台程序的模仿copy

(1) 首先新建一个控制台应用程序，起名随便，然后写入如下代码：

static void Main(string[] args)
 
{
 
            //保证给的参数只有两个
 
            if (args.Length != 2)
 
            {
 
                Console.WriteLine("命令语法不正确");
 
                return;
 
            }
 
            //得到文件的路径
 
            string file1 = args[0];
 
            string file2 = args[1];
 
            //判断第一个文件是否存在
 
            try
 
            {
 
                using (FileStream fileRead = new FileStream(file1, FileMode.Open, FileAccess.Read))
 
                {
 
                    using (FileStream fileWrite = new FileStream(file2, FileMode.Create, FileAccess.Write))
 
                    {
 
                        byte[] bs = new byte[10 * 1024];
 
                        int count = 0;
 
                        while ((count = fileRead.Read(bs, 0, bs.Length)) > 0)
 
                        {
 
                            fileWrite.Write(bs, 0, count);
 
                        }
 
                        Console.WriteLine("以复制\t\t1个文件");
 
                    }
 
                }
 
            }
 
            catch
 
            {
 
                Console.WriteLine("系统找不到指定文件");
 
            }
 
}