I/O即input/output(输入和输出)的首字母缩写,顾名思义是程序对数据的输入和输出操作。输入指的是通过外接设备、文件向程序写入内容,输出是程序向外界设备输出内容,参照物是程序本身。IO中通过File类创建文件、复制、删除文件等,通过Directory创建文件夹,打印文件夹中文件名等。IO中通过流来读写数据,常见的流有:一.FileStream(是一个双向流,既可以读也可以写)、二.StreamWriter(进行字符操作、单向流---输出)(有以下几种常见参数类型:1(Stream stream)传入Stream流对象。2(string path)路径。3(string path,bool append)路径,是否追加(true or false)。4(string path,bool append,Encoding.UTF8)路径,是否追加(true or false),编码格式。)、StreamReader(进行字符操作、单向流---输入)、三.BinaryReader(进行字节操作)、BinaryWriter(进行字节操作)、四.BufferedStream。关系如下:
这四类流对数据的读写操作的具体事例有:
一.FileStream有关操作
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1 //FileStream创建文件并向文件中写入内容 2 using System; 3 using System.Collections.Generic; 4 using System.Linq; 5 using System.Text; 6 using System.IO; 7 8 namespace ConsoleApplication1 9 { 10 class Program 11 { 12 static void Main(string[] args) 13 { 14 //创建FileStream对象来创建或打开文件 15 FileStream fs = File.Open(@"d:\1.cs", FileMode.OpenOrCreate); 16 StringBuilder sb = new StringBuilder(); 17 //用StringBuilder对象获取要写入的内容块 18 sb.Append(@"using System; 19 using System.Collections.Generic; 20 using System.Linq; 21 using System.Text; 22 using System.IO; 23 24 namespace ConsoleApplication1 25 { 26 class Program 27 { 28 static void Main(string[] args) 29 { 30 //创建文件 31 File.Create(@""d:\1.cs""); 32 /*---向文件中写入内容---*/ 33 //创建FileStream对象来打开已创建文件 34 FileStream fs = File.Open(@""d:\1.cs"", FileMode.Open); 35 StringBuilder sb = new StringBuilder(); 36 sb.Append(@""追加内容""); 37 byte[] buffer = Encoding.UTF8.GetBytes(sb.ToString()); 38 fs.Write(buffer, 0, buffer.Length); 39 fs.Close(); 40 } 41 } 42 }"); 43 //定义buffer缓冲区,把StringBuilder对象的内容转化成UTF8的字节类型放入缓冲区 44 byte[] buffer = Encoding.UTF8.GetBytes(sb.ToString()); 45 //从缓冲区中的内容向文件的第0个位置开始写,写入buffer.Length的字节长度 46 fs.Write(buffer, 0, buffer.Length); 47 //最后关闭FileStream流 48 fs.Close(); 49 } 50 } 51 } 52 //FileStream输出从文件中读取的内容 53 using System; 54 using System.Collections.Generic; 55 using System.Linq; 56 using System.Text; 57 using System.IO; 58 59 namespace ConsoleApplication1 60 { 61 class Program 62 { 63 static void Main(string[] args) 64 { 65 FileStream fs = File.Open(@"d:\1.cs", FileMode.Open); 66 //默认缓冲区为1024字节,每次从文件流获取1024字节放入缓冲区 67 byte[] buffer = new byte[1024]; 68 //i代表已经读取的字节数,若i=0,则已经读取文件末尾,从而结束循环 69 int i = 0; 70 string result = ""; 71 //当程序读取文件时,把从缓冲区读取的字节从第一个元素开始放置,直到buffer.Length 72 while ((i = fs.Read(buffer, 0, buffer.Length)) != 0) 73 { 74 result += Encoding.UTF8.GetString(buffer, 0, i); 75 } 76 //关闭流 77 fs.Close(); 78 Console.WriteLine(result); 79 } 80 } 81 } 82 //FileStream从文件中只读取的1024字节内容(不完善的读操作) 83 using System; 84 using System.Collections.Generic; 85 using System.Linq; 86 using System.Text; 87 using System.IO; 88 89 namespace ConsoleApplication1 90 { 91 class Program 92 { 93 static void Main(string[] args) 94 { 95 FileStream fs = File.Open(@"d:\1.cs", FileMode.Open); 96 byte[] buffer = new byte[1024]; 97 fs.Read(buffer, 0, buffer.Length); 98 string result = Encoding.UTF8.GetString(buffer); 99 fs.Close(); 100 Console.WriteLine(result); 101 } 102 } 103 } 104 //FileStream 复制文件 105 using System; 106 using System.Collections.Generic; 107 using System.Linq; 108 using System.Text; 109 using System.IO; 110 111 namespace ConsoleApplication1 112 { 113 class Program 114 { 115 static void Main(string[] args) 116 { 117 FileStream read = File.Open(@"d:\1.cs", FileMode.Open); 118 FileStream write = File.Open(@"e:\1.cs", FileMode.OpenOrCreate); 119 byte[] buffer = new byte[1024]; 120 int i = 0; 121 while ((i = read.Read(buffer, 0, buffer.Length)) != 0) 122 { 123 write.Write(buffer,0,i); 124 } 125 write.Close(); 126 read.Close(); 127 } 128 } 129 } 130 //FileStream 边复制文件边打印进度 131 namespace ConsoleApplication1 132 { 133 class Program 134 { 135 static void Main(string[] args) 136 { 137 FileStream read = File.Open(@"d:\1.cs", FileMode.Open); 138 //定义count,标识文件总大小 139 long count = read.Length; 140 FileStream write = File.Open(@"e:\1.cs", FileMode.OpenOrCreate); 141 byte[] buffer = new byte[1024]; 142 int i = 0; 143 //定义ri,获取已经读取的文件 144 int ri = 0; 145 while ((i = read.Read(buffer, 0, buffer.Length)) != 0) 146 { 147 write.Write(buffer,0,i); 148 ri += i; 149 string s = ((double)ri / count * 100).ToString("0.00") + "%"; 150 Console.WriteLine(s); 151 } 152 write.Close(); 153 read.Close(); 154 } 155 } 156 } 157 //FileStream 剪切文件: 158 using System; 159 using System.Collections.Generic; 160 using System.Linq; 161 using System.Text; 162 using System.IO; 163 164 namespace ConsoleApplication1 165 { 166 class Program 167 { 168 static void Main(string[] args) 169 { 170 //复制操作 171 FileStream read = File.Open(@"d:\1.cs", FileMode.Open); 172 FileStream write = File.Open(@"e:\1.cs", FileMode.OpenOrCreate); 173 byte[] buffer = new byte[1024]; 174 int i = 0; 175 while ((i = read.Read(buffer, 0, buffer.Length)) != 0) 176 { 177 write.Write(buffer,0,i); 178 } 179 write.Close(); 180 read.Close(); 181 //复制后删除源文件 182 File.Delete(@"d:\1.cs"); 183 } 184 } 185 }
二.StreamReader、StreamWriter对数据的有关操作
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1 //使用StreamReader单独操作字符进行读操作 2 using System; 3 using System.Collections.Generic; 4 using System.Linq; 5 using System.Text; 6 using System.IO; 7 8 namespace ConsoleApplication1 9 { 10 class Program 11 { 12 static void Main(string[] args) 13 { 14 //操作字符 15 //StreamReader reader = new StreamReader(@"d:\1.cs"); 16 StreamReader reader = new StreamReader(@"d:\1.cs",Encoding.UTF8); 17 string str = reader.ReadToEnd(); 18 Console.WriteLine(str); 19 reader.Close(); 20 } 21 } 22 } 23 //用StreamReader通过ReadLine单行读取,操作字符输出读取的内容 24 using System; 25 using System.Collections.Generic; 26 using System.Linq; 27 using System.Text; 28 using System.IO; 29 30 namespace ConsoleApplication1 31 { 32 class Program 33 { 34 static void Main(string[] args) 35 { 36 //操作字符 37 StreamReader reader = new StreamReader(@"d:\1.cs"); 38 string str = reader.ReadLine(); 39 while (str != null) 40 { 41 Console.WriteLine(str); 42 str = reader.ReadLine(); 43 } 44 reader.Close(); 45 } 46 } 47 } 48 //使用StreamWriter单独操作字符进行写操作 49 using System; 50 using System.Collections.Generic; 51 using System.Linq; 52 using System.Text; 53 using System.IO; 54 55 namespace ConsoleApplication1 56 { 57 class Program 58 { 59 static void Main(string[] args) 60 { 61 //操作字符,true表示执行写操作的时候在原内容基础上追加。 62 StreamWriter writer = new StreamWriter(@"d:\1.cs",true,Encoding.UTF8); 63 writer.Write("写入文件的内容:……"); 64 writer.Close(); 65 } 66 } 67 //使用FileStream流设置文件写操作时的追加效果设置(避免向文件中写内容时覆盖掉文件中原存内容),从而代替StreamWriter参数中true的设置,效果同上 68 using System; 69 using System.Collections.Generic; 70 using System.Linq; 71 using System.Text; 72 using System.IO; 73 74 namespace ConsoleApplication1 75 { 76 class Program 77 { 78 static void Main(string[] args) 79 { 80 FileStream stream = File.Open(@"d:\1.cs", FileMode.Append); 81 StreamWriter writer = new StreamWriter(stream); 82 writer.Write("写入文件的内容:……"); 83 writer.Close(); 84 } 85 } 86 }
三.BinaryReader、BinaryWriter有关的数据操作
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1 //BinaryReader读操作 2 using System; 3 using System.Collections.Generic; 4 using System.Linq; 5 using System.Text; 6 using System.IO; 7 8 namespace ConsoleApplication1 9 { 10 class Program 11 { 12 static void Main(string[] args) 13 { 14 FileStream stream = File.Open(@"d:\1.cs", FileMode.Open); 15 BinaryReader reader = new BinaryReader(stream); 16 byte[] buffer = new byte[1024]; 17 int i = 0; 18 string str = ""; 19 while ((i = reader.Read(buffer, 0, buffer.Length)) != 0) 20 { 21 str += Encoding.UTF8.GetString(buffer, 0, i); 22 } 23 reader.Close(); 24 stream.Close(); 25 Console.WriteLine(str); 26 } 27 } 28 } 29 //BinaryWriter写操作 30 using System; 31 using System.Collections.Generic; 32 using System.Linq; 33 using System.Text; 34 using System.IO; 35 36 namespace ConsoleApplication1 37 { 38 class Program 39 { 40 static void Main(string[] args) 41 { 42 FileStream stream = File.Open(@"d:\1.cs", FileMode.OpenOrCreate); 43 BinaryWriter writer = new BinaryWriter(stream); 44 string str = "这是写入的内容"; 45 byte[] buffer = Encoding.UTF8.GetBytes(str); 46 writer.Write(buffer, 0, buffer.Length); 47 writer.Close(); 48 stream.Close(); 49 } 50 } 51 }
四.利用BufferedStream进行读写操作
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1 //BufferedStream读操作 2 using System; 3 using System.Collections.Generic; 4 using System.Linq; 5 using System.Text; 6 using System.IO; 7 8 namespace ConsoleApplication1 9 { 10 class Program 11 { 12 static void Main(string[] args) 13 { 14 Stream streamReader = File.Open(@"d:\1.cs",FileMode.Open); 15 BufferedStream stream = new BufferedStream(streamReader); 16 byte[] buffer = new byte[1024]; 17 int i = 0; 18 string str = ""; 19 while ((i = streamReader.Read(buffer, 0, buffer.Length)) != 0) 20 { 21 str += Encoding.UTF8.GetString(buffer, 0, i); 22 } 23 stream.Close(); 24 streamReader.Close(); 25 Console.WriteLine(str); 26 } 27 } 28 } 29 //BufferedStream写操作 30 using System; 31 using System.Collections.Generic; 32 using System.Linq; 33 using System.Text; 34 using System.IO; 35 36 namespace ConsoleApplication1 37 { 38 class Program 39 { 40 static void Main(string[] args) 41 { 42 Stream streamWriter = File.Open(@"d:\1.cs",FileMode.OpenOrCreate); 43 BufferedStream stream = new BufferedStream(streamWriter); 44 StringBuilder sb = new StringBuilder(); 45 sb.Append(@"这是写入的内容:…… 46 "); 47 byte[] buffer = Encoding.UTF8.GetBytes(sb.ToString()); 48 stream.Write(buffer, 0, buffer.Length); 49 stream.Close(); 50 streamWriter.Close(); 51 } 52 } 53 }
了解了IO中流对数据的读写操作以及复制原理后,我们还可以使用File类的方法直接对文件执行复制、删除等操作:
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1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.IO; 6 7 namespace ConsoleApplication1 8 { 9 class Program 10 { 11 static void Main(string[] args) 12 { 13 //创建文件 14 //File.Create(@"d:\1.mp3"); 15 //拷贝文件 16 //File.Copy(@"d:\1.mp3",@"d:\2.mp3"); 17 //删除文件 18 //File.Delete(@"d:\2.mp3"); 19 //移动文件 20 //File.Move(@"d:\1.mp3", @"e:\1.mp3"); 21 //获取创建文件时间 22 DateTime dt = File.GetCreationTime(@"e:\1.mp3"); 23 Console.WriteLine(dt); 24 25 } 26 } 27 }
Directory 利用目录可以在制定位置直接创建文件夹等:
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1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.IO; 6 7 namespace ConsoleApplication1 8 { 9 class Program 10 { 11 static void Main(string[] args) 12 { 13 //创建文件夹 14 //Directory.CreateDirectory(@"d:\my"); 15 //获取文件夹中所有文件 16 //string[] strs = Directory.GetFiles(@"d:\my"); 17 //foreach (string str in strs) 18 //{ 19 // Console.WriteLine(str); 20 //} 21 //获取文件夹下的文件夹中的文件 22 string[] strs = Directory.GetFileSystemEntries(@"d:\my"); 23 foreach (string str in strs) 24 { 25 if (Directory.Exists(str)) 26 { 27 string[] ss = Directory.GetFileSystemEntries(str); 28 foreach (string s in ss) 29 { 30 Console.WriteLine(s); 31 } 32 } 33 } 34 } 35 } 36 }