C# 文件操作类

using System;
using System.IO;

namespace Utils
{
public class IOHelper
{
public IOHelper();

public static bool CopyDir(DirectoryInfo fromDir, string toDir); //复制目录
public static bool CopyDir(string fromDir, string toDir); //复制目录
public static bool CreateDir(string dirName); //创建目录
public static bool CreateFile(string fileName); //创建文件
public static void DeleteDir(DirectoryInfo dir); //删除目录 （如果目录中存在文件就删除）
public static bool DeleteDir(string dir, bool onlyDir); //删除目录
public static bool DeleteFile(string fileName);//删除文件
public static bool Exists(string fileName);//判断文件是否存在
public static bool FindFile(DirectoryInfo dir, string fileName);//在指定的目录中查找文件
public static bool FindFile(string dir, string fileName);//在指定的目录中查找文件
public static string Read(string fileName);//读文件的全部内容
public static string ReadLine(string fileName);//读第一行数据
public static bool Write(string fileName, string content);//写入指定的内容

public static bool WriteLine(string fileName, string content);//写一行数据
}
}

using System;
using System.Text;
using System.IO;
/*----------------------------------------------------------------
//文件名：IOHelper
//文件功能描述：文件操作类
//
//创建人:陈太汉
//创建日期：2011/05/18

----------------------------------------------------------------*/
namespace Utils
{
public class IOHelper
{
/// <summary>
/// 判断文件是否存在
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public static bool Exists(string fileName)
{
if (fileName == null || fileName.Trim() == "")
{
return false;
}

if (File.Exists(fileName))
{
return true;
}

return false;
}


/// <summary>
/// 创建文件夹
/// </summary>
/// <param name="dirName"></param>
/// <returns></returns>
public static bool CreateDir(string dirName)
{
if (!Directory.Exists(dirName))
{
Directory.CreateDirectory(dirName);
}
return true;
}


/// <summary>
/// 创建文件
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public static bool CreateFile(string fileName)
{
if (!File.Exists(fileName))
{
FileStream fs = File.Create(fileName);
fs.Close();
fs.Dispose();
}
return true;

}


/// <summary>
/// 读文件内容
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public static string Read(string fileName)
{
if (!Exists(fileName))
{
return null;
}
//将文件信息读入流中
using (FileStream fs = new FileStream(fileName, FileMode.Open))
{
return new StreamReader(fs).ReadToEnd();
}
}


public static string ReadLine(string fileName)
{
if (!Exists(fileName))
{
return null;
}
using (FileStream fs = new FileStream(fileName, FileMode.Open))
{
return new StreamReader(fs).ReadLine();
}
}


/// <summary>
/// 写文件
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="content">文件内容</param>
/// <returns></returns>
public static bool Write(string fileName, string content)
{
if (!Exists(fileName) || content == null)
{
return false;
}

//将文件信息读入流中
using (FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate))
{
lock (fs)//锁住流
{
if (!fs.CanWrite)
{
throw new System.Security.SecurityException("文件fileName=" + fileName + "是只读文件不能写入!");
}

byte[] buffer = Encoding.Default.GetBytes(content);
fs.Write(buffer, 0, buffer.Length);
return true;
}
}
}


/// <summary>
/// 写入一行
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="content">内容</param>
/// <returns></returns>
public static bool WriteLine(string fileName, string content)
{
using (FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate | FileMode.Append))
{
lock (fs)
{
if (!fs.CanWrite)
{
throw new System.Security.SecurityException("文件fileName=" + fileName + "是只读文件不能写入!");
}

StreamWriter sw = new StreamWriter(fs);
sw.WriteLine(content);
sw.Dispose();
sw.Close();
return true;
}
}
}


public static bool CopyDir(DirectoryInfo fromDir, string toDir)
{
return CopyDir(fromDir, toDir, fromDir.FullName);
}


/// <summary>
/// 复制目录
/// </summary>
/// <param name="fromDir">被复制的目录</param>
/// <param name="toDir">复制到的目录</param>
/// <returns></returns>
public static bool CopyDir(string fromDir, string toDir)
{
if (fromDir == null || toDir == null)
{
throw new NullReferenceException("参数为空");
}

if (fromDir == toDir)
{
throw new Exception("两个目录都是" + fromDir);
}

if (!Directory.Exists(fromDir))
{
throw new IOException("目录fromDir="+fromDir+"不存在");
}

DirectoryInfo dir = new DirectoryInfo(fromDir);
return CopyDir(dir, toDir, dir.FullName);
}


/// <summary>
/// 复制目录
/// </summary>
/// <param name="fromDir">被复制的目录</param>
/// <param name="toDir">复制到的目录</param>
/// <param name="rootDir">被复制的根目录</param>
/// <returns></returns>
private static bool CopyDir(DirectoryInfo fromDir, string toDir, string rootDir)
{
string filePath = string.Empty;
foreach (FileInfo f in fromDir.GetFiles())
{
filePath = toDir + f.FullName.Substring(rootDir.Length);
string newDir = filePath.Substring(0, filePath.LastIndexOf("\\"));
CreateDir(newDir);
File.Copy(f.FullName, filePath, true);
}

foreach (DirectoryInfo dir in fromDir.GetDirectories())
{
CopyDir(dir, toDir, rootDir);
}

return true;
}


/// <summary>
/// 删除文件
/// </summary>
/// <param name="fileName">文件的完整路径</param>
/// <returns></returns>
public static bool DeleteFile(string fileName)
{
if (Exists(fileName))
{
File.Delete(fileName);
return true;
}
return false;
}


public static void DeleteDir(DirectoryInfo dir)
{
if (dir == null)
{
throw new NullReferenceException("目录不存在");
}

foreach (DirectoryInfo d in dir.GetDirectories())
{
DeleteDir(d);
}

foreach (FileInfo f in dir.GetFiles())
{
DeleteFile(f.FullName);
}

dir.Delete();

}


/// <summary>
/// 删除目录
/// </summary>
/// <param name="dir">制定目录</param>
/// <param name="onlyDir">是否只删除目录</param>
/// <returns></returns>
public static bool DeleteDir(string dir, bool onlyDir)
{
if (dir == null || dir.Trim() == "")
{
throw new NullReferenceException("目录dir=" + dir + "不存在");
}

if (!Directory.Exists(dir))
{
return false;
}

DirectoryInfo dirInfo = new DirectoryInfo(dir);
if (dirInfo.GetFiles().Length == 0 && dirInfo.GetDirectories().Length==0)
{
Directory.Delete(dir);
return true;
}


if (!onlyDir)
{
return false;
}
else
{
DeleteDir(dirInfo);
return true;
}

}


/// <summary>
/// 在指定的目录中查找文件
/// </summary>
/// <param name="dir">目录</param>
/// <param name="fileName">文件名</param>
/// <returns></returns>
public static bool FindFile(string dir, string fileName)
{
if (dir == null || dir.Trim() == "" || fileName == null || fileName.Trim() == "" || !Directory.Exists(dir))
{
return false;
}

DirectoryInfo dirInfo = new DirectoryInfo(dir);
return FindFile(dirInfo, fileName);

}


public static bool FindFile(DirectoryInfo dir, string fileName)
{
foreach (DirectoryInfo d in dir.GetDirectories())
{
if (File.Exists(d.FullName + "\\" + fileName))
{
return true;
}
FindFile(d,fileName);
}

return false;
}

}
}

http://www.cnblogs.com/leo_wl/archive/2011/10/19/2217601.html