文件读写操作

r囧r小猫 2021-12-24 15:07 377阅读 0赞

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] Code   
using System;  
using System.IO;  
/\*从文本文件中读或者写文本时，首先需创建一个与文件相关的StreamReader或者StreamWriter对象  
每一个StreamReader或StreamWriter对象都与一种字符编码方式相关。默认UTF8Encoding  
\*/  
class FileOperate  
\{  
publicstaticstring content="";  
publicstatic StreamReader sr=null;  
publicstatic StreamWriter sw=null;  
//读取文本时，有许多方法可以创建与文件名相关的Streamreader对象   
///<summary>  
///方法一： 从文件名直接创建  
///</summary>  
publicvoid ReadFromFileName()  
\{  
  
try  
\{  
sr=new StreamReader ("TestFile.txt");  
string txt="";  
while((txt=sr.ReadLine())!=null)  
\{  
content\+=txt;  
\}  
Console.WriteLine ("\----ReadFromFileName------");  
Console.WriteLine (content);  
\}  
catch(Exception ex)  
\{  
Console.WriteLine (ex.Message);  
\}  
finally  
\{  
sr.Close ();  
\}  
  
\}  
///<summary>  
///方法二： 使用File类或者FileInfo类的OpenText方法创建  
///</summary>  
publicvoid ReadUseFileOrFileInfo()  
\{  
  
try  
\{  
FileInfo fi=new FileInfo ("TestFile.txt");  
sr=fi.OpenText();  
content="";  
while(!sr.EndOfStream)  
\{  
content\+=sr.ReadLine();  
\}  
Console.WriteLine ("\----ReadUseFileOrFileInfo------");  
Console.WriteLine (content);  
\}  
catch(Exception ex)  
\{  
Console.WriteLine (ex.Message);  
\}  
finally  
\{  
sr.Close ();  
\}  
  
\}  
  
///<summary>  
/// 方法3：通过FileStream对象创建  
///</summary>  
publicvoid ReadThroughFileStream()  
\{  
//打开文件 只读  
 FileStream fs1=new FileStream("TestFile.txt",FileMode.Open,FileAccess.Read );  
//打开文件 读写  
//FileStream fs2=File.Open ("TestFile.txt",FileMode.Open ,FileAccess.ReadWrite);  
//打开文件 读写  
//FileStream fs3=File.Create("TestFile.txt");  
//打开文件 只读  
//FileStream fs4=File.OpenRead("TestFile.txt");  
  
try  
\{  
sr=new StreamReader (fs1);  
content="";  
while(!sr.EndOfStream)  
\{  
content\+=sr.ReadLine();  
\}  
Console.WriteLine ("\----ReadThroughFileStream------");  
Console.WriteLine (content);  
\}  
catch(Exception ex)  
\{  
Console.WriteLine (ex.Message);  
\}  
finally  
\{  
fs1.Close ();  
sr.Close ();  
\}  
\}  
//写入文件 三种方式  
///<summary>  
/// 方法一：通过文件名创建  
///</summary>  
publicvoid WriteFromFileName()  
\{  
try  
\{  
sw=new StreamWriter("TestFile.txt");  
Console.WriteLine ("Input Write File's Content:");  
string lines=Console.ReadLine ();  
sw.WriteLine(lines);  
\}  
catch(Exception ex)  
\{  
Console.WriteLine (ex.Message );  
\}  
finally  
\{  
sw.Close ();  
\}  
\}  
///<summary>  
/// 文件写入方法二：使用File类或者FileInfo类的CreateText或AppendText方法来创建  
/// AppendText方法：对于文件内容进行追加 CreateText方法：会删除已经存在的文件  
/// 缺点：只能创建支持UTF8Encoding的StreamWriter对象  
///</summary>  
publicvoid WriteUseFileOrFileInfo()  
\{  
//File类的CreateText方法  
 StreamWriter sw1=File.CreateText("TestFile.txt");  
sw1.WriteLine("File类的CreateText方法");  
sw1.Close ();  
//FileInfo CreateText   
 FileInfo fi1=new FileInfo ("TestFile.txt");  
StreamWriter sw2=fi1.CreateText();  
sw2.WriteLine("FileInfo CreateText ");  
sw2.Close ();  
//File类的AppendText方法  
 StreamWriter sw3=File.AppendText("TestFile.txt");  
sw3.WriteLine("File类的AppendText方法");  
sw3.Close ();  
//FileInfo 的AppendText  
 FileInfo fi2=new FileInfo ("TestFile.txt");  
StreamWriter sw4=fi2.AppendText();  
sw4.WriteLine("FileInfo 的AppendText");  
sw4.Close ();  
\}  
///<summary>  
/// 通过FileStream对象来创建  
///</summary>  
publicvoid WriteThroughFileStream()  
\{  
  
//打开文件 只写  
 FileStream fs1=new FileStream("TestFile.txt",FileMode.Open,FileAccess.Write);  
StreamWriter sw1=new StreamWriter(fs1);  
sw1.WriteLine("通过FileStream对象来创建");  
sw1.Close ();  
fs1.Close ();  
//打开文件 读写  
 FileStream fs2=File.Open ("TestFile.txt",FileMode.Open ,FileAccess.ReadWrite);  
StreamWriter sw2=new StreamWriter(fs2);  
sw2.WriteLine("通过File.Open创建FileStream对象");  
sw2.Close ();  
fs2.Close ();  
//打开文件 读写  
 FileStream fs3=File.Create("TestFile.txt");  
StreamWriter sw3=new StreamWriter(fs3);  
sw3.WriteLine("通过File.Create创建FileStream对象");  
sw3.Close ();  
fs3.Close ();  
//打开文件 只写  
 FileStream fs4=File.OpenWrite("TestFile.txt");  
StreamWriter sw4=new StreamWriter(fs4);  
sw4.WriteLine("通过File.OpenWrite创建FileStream对象");  
sw4.Close ();  
fs4.Close ();  
\}  
  
///<summary>  
/// 二进制文件读写  
///</summary>  
  
publicvoid ByteReadWrite()  
\{  
FileStream fs =new FileStream("TestFile.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite);//创建文件   
 StreamWriter sw =new StreamWriter(fs);  
// 以文本方式写一个文件  
 sw.WriteLine("Hello, World");  
sw.WriteLine("你好吗?");  
sw.WriteLine("我很好!");  
sw.WriteLine("嘿嘿，示例好傻!");  
sw.Flush(); //清理缓冲区  
 StreamReader sr =new StreamReader(fs);  
sr.BaseStream.Seek(0, SeekOrigin.Begin);//定位到流的开始位置   
string str=string.Empty;  
while (!sr.EndOfStream) //未到文件流结尾  
 \{  
str\+= sr.ReadLine();  
\}  
BinaryReader br =new BinaryReader(fs);  
br.BaseStream.Seek(0, SeekOrigin.Begin);//定位到流的开始位置   
 Byte b =new Byte();  
while (br.PeekChar() >\-1)//定位到下一个字符  
 \{  
b \+= br.ReadByte();  
\}  
//关闭文件流  
 sw.Close();  
br.Close();  
sr.Close();  
fs.Close();  
  
\}  
  
publicstaticvoid Main(string\[\] args)  
\{  
FileOperate ofile=new FileOperate();  
//读取文件写入文件   
 ofile.WriteFromFileName();  
ofile.ReadFromFileName();  
ofile.WriteUseFileOrFileInfo();  
ofile.ReadUseFileOrFileInfo();  
ofile.WriteThroughFileStream();  
ofile.ReadThroughFileStream();  
ofile.ByteReadWrite();  
Console.ReadLine();  
\}  
  
\}

转载于:https://www.cnblogs.com/hubcarl/archive/2009/07/13/1522541.html

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