C# 文件操作

在.NET Framework中进行的所有的输入和输出工作都要用到流(stream),流是序列化设备(serial device)的抽象表示。

System.IO包含了用于在文件中读写数据的类。

File 类 静态实用类 提供静态方法 用于移动 复制和删除文件

Directory 类静态实用类 提供静态方法 用于移动 复制和删除文件

Path 类 用于处理路径名称

FileInfo 类 表示磁盘上的物理文件,该类包含处理文件的方法。要完成对文件的读写工作,必须创建Stream对象。

DirectoryInfo 类 表示磁盘上的文件,包含处理目录的方法。

FileStreamInfo 用作FileInfo和DirectoryInfo的基类,可以使用多态性同时处理文件和目录。

FileStream类 表示可读可写,或者均可的文件,此文件可以同步或一部的读写。

SreamReader 从流中读取字符数据,可使用FileStream将其创建为基类。

StreamWriter 向流中写入数据,使用FileStream将其创建为基类。

FileSystemWatcher 用于监控文件和目录,提供了这些文件和目录发生变化时应用程序可以捕获的事件。

 

System.IO.Compression 它允许使用GZIP压缩或Default压缩模式读写压缩文件。

System.Runtime.Serialization.Formatters.Binary命名空间中的BinaryFormatter类允许把对象序列化为二进制数据流,并可以反序列化这些数据。

 

FileStream aFile = new FileStream(filename,FileMode.Member,FileAccess.Member);

FileStream aFile = File.OpenRead(“Data.txt”);

FileInfo aFileInfo = new FileInfo(“Data.txt”);

FileStream aFile = aFileInfo.OpenRead();

 

DirectoryInfo dir = new DirectoryInfo(Path);

FileSystemInfo[]fsi = dir.GetFileSystemInfos);//获取所有子目录及文件

 

文件位置

Seek()方法。

AFile.Seek(8,SeekOrigin.Begin);//将文件指针移动到文件的第八个字节。

FileStream myReadStream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Read);
            myReadStream.Seek(6, SeekOrigin.Begin);
            myReadStream.Read(byData, 0, 128);

StreamReader

实现一个 TextReader,使其以一种特定的编码从字节流中读取字符。

StreamReader 旨在以一种特定的编码输入字符,而 Stream 类用于字节的输入和输出。使用 StreamReader 读取标准文本文件的各行信息。

除非另外指定,StreamReader 的默认编码为 UTF-8,而不是当前系统的 ANSI 代码页。UTF-8 可以正确处理 Unicode 字符并在操作系统的本地化版本上提供一致的结果。

View Code
try 
        {
            // Create an instance of StreamReader to read from a file.
            // The using statement also closes the StreamReader.
            using (StreamReader sr = new StreamReader("TestFile.txt")) 
            {
                String line;
                // Read and display lines from the file until the end of 
                // the file is reached.
                while ((line = sr.ReadLine()) != null) 
                {
                    Console.WriteLine(line);
                }
            }
        }
        catch (Exception e) 
        {
            // Let the user know what went wrong.
            Console.WriteLine("The file could not be read:");
            Console.WriteLine(e.Message);
        }
View Code
string path = @"c:\temp\MyTest.txt";
        try 
        {
            if (File.Exists(path)) 
            {
                File.Delete(path);
            }

            using (StreamWriter sw = new StreamWriter(path)) 
            {
                sw.WriteLine("This");
                sw.WriteLine("is some text");
                sw.WriteLine("to test");
                sw.WriteLine("Reading");
            }

            using (StreamReader sr = new StreamReader(path)) 
            {
                while (sr.Peek() >= 0) 
                {
                    Console.WriteLine(sr.ReadLine());
                }
            }
        } 
        catch (Exception e) 
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }

读取数据最简单的方法是Read()方法。

此方法将流的下一个字符作为正整数值返回,如果达到流的结尾处,返回-1.使用Convert实用类把这个值转化为字符。

StreamReader  sr = new  StreamReader();

Int nChar;

nChar=sr.Read();

While(nChar!=-1)

{

Console.Write(Convert.ToChar(nChar));

nChar = sr.Read();

}

Sr.Close();

StreamWriter 类

实现一个 TextWriter,使其以一种特定的编码向流中写入字符。

FileStream fs = new FileStream(fileName,  FileMode.CreateNew, FileAccess.Write, FileShare.None);      

           StreamWriter swFromFile = new StreamWriter(logFile);

            swFromFile.Write(textToAdd);

            swFromFile.Flush();

            swFromFile.Close();

文件属性

FileInfo fileInfo = new FileInfo(path);

//去掉隐藏属性

fileInfo.Attributes &= ~FileAttributes.Hidden;

//去掉只读属性

fileInfo.Attributes &= ~FileAttributes.ReadOnly;

添加隐藏属性

fileInfo.Attributes |= FileAttributes.Hidden;

GetAttibutes()和SetAttributes()方法可以获取或设定文件属性。

查找指定目录下的所有子目录和文件
 public void FindFile(string dir)
        {
            string[] Alldir = Directory.GetDirectories(dir);
            try
            {
                foreach (string Strdir in Alldir)
                {
                    FindFile(Strdir + "\\");
                    listBox1.Items.Add(Strdir + "\\");//添加目录名
                }
                foreach (string Strfile in Directory.GetFiles(dir))
                {
                    listBox1.Items.Add(Strfile);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string path = "";
            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
            {
                path = folderBrowserDialog1.SelectedPath;
            }
            if (path.Length > 1)
            {
                if (path[path.Length - 1] != '\\')
                {
                    path += "\\";
                }
            }
            FindFile(path);
            //DirectoryInfo dir = new DirectoryInfo(path);
            //FileSystemInfo[] fsi = dir.GetFileSystemInfos();
            //foreach (FileSystemInfo f in fsi)
            //{
            //    listBox1.Items.Add(f.FullName);
            //}
        }
读写压缩文件
 public static void SaveCompressionFile(string fileName, string data)
        {
            FileStream fileStream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write);
            GZipStream compressionStream = new GZipStream(fileStream, CompressionMode.Compress);
            StreamWriter writer = new StreamWriter(compressionStream);
            writer.Write(data);
            writer.Close();
        }

        public static string LoadCompressionFile(string fileName)
        {
            FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read);
            GZipStream compressionStream = new GZipStream(fileStream, CompressionMode.Decompress);
            StreamReader reader = new StreamReader(compressionStream);
            string data = reader.ReadToEnd();
            return data;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string path = "";
            openFileDialog1.InitialDirectory = "c:\\";
            openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
            openFileDialog1.FilterIndex = 2;
            openFileDialog1.RestoreDirectory = true;

            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {    
                    path = openFileDialog1.FileName;
                    //return new FileStream(path, System.IO.FileMode.Open,System.IO.FileAccess.ReadWrite);
            }
            try
            {
                label1.Text = textBox1.Text.Length.ToString();
                SaveCompressionFile(path, textBox1.Text.Trim());
                FileInfo fileInfo = new FileInfo(path);
                label2.Text = fileInfo.Length.ToString();
                textBox2.Text = LoadCompressionFile(path);
            }
            catch(IOException ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
计算机上的驱动器
class Program
    {
        static void Main(string[] args)
        {
            DriveInfo[] Drives;
            ArrayList hardDisk = new ArrayList(); ;
            Drives = DriveInfo.GetDrives();
            int drvCount = Drives.Length;
            Console.WriteLine("本地计算机上共有逻辑驱动器 " + drvCount + " 个,分别是:");
            foreach (DriveInfo item in Drives)
            {
                Console.Write(item + "\t");
                if (item.DriveType == DriveType.Fixed)
                {
                    hardDisk.Add(item.ToString());
                }
            }
            Console.WriteLine("\n本地计算机上共有本地驱动器 " + hardDisk.Count + " 个,分别是:");
            foreach (var Disk in hardDisk)
            {
                Console.Write(Disk + "\t");
            }
            string drvName = @"E:\";
            DriveInfo drvInfo = new DriveInfo(drvName);
            Console.WriteLine("驱动器E的信息如下:");
            Console.WriteLine("名 称: " + drvInfo.Name);
            Console.WriteLine("卷 标: " + drvInfo.VolumeLabel);
            Console.WriteLine("驱动器类型: " + drvInfo.DriveType);
            Console.WriteLine("文件系统类型: " + drvInfo.DriveFormat);
            Console.WriteLine("总共空间大小:" + drvInfo.TotalSize);
            Console.WriteLine("剩余空间大小:" + drvInfo.TotalFreeSpace);
            Console.WriteLine("根目录:" + drvInfo .RootDirectory );

            //string path = @"D:\My Documents";
            //string[] AllFile = Directory.GetFiles(path);
            //ArrayList picFile = new ArrayList();

            //for (int i = 0; i < AllFile.Length; i++)
            //{
            //    FileInfo fi = new FileInfo(AllFile[i]);
            //    if (fi.Extension == ".jpg" || fi.Extension == ".bmp")
            //        picFile.Add(AllFile[i]);
            //}
            //foreach (string file in picFile)
            //{
            //    Console.WriteLine(file);
            //}
            //Console.WriteLine("共找到符合条件的:{0}个文件", picFile.Count.ToString());
            //string path = @"C:\aaa\bbb\ccc\dddd";
            //if (!Directory.Exists(path))
            //{
            //    Directory.CreateDirectory(path);
            //} 
            ////Directory类的Exists()方法用来判断目录是否存在,存在则返回true;  
            ////Directory类的CreateDirectory()方法用来创建目录  

            //得到所有文件
            //string[] AllFile = Directory.GetFiles(@"d:\Test");
            //foreach (string file in AllFile)
            //{
            //    File.Delete(file);
            //}


            //string filepath = @"D:\WorkList.txt";
            ////string filepath = @"F:\VStest\file.txt";
            //FileInfo myfile = new FileInfo(filepath);
            //FileStream fs = myfile.Create();
            //fs.Close();
            //myfile.Refresh();
            //myfile.Delete();


            Console.ReadKey();
        }
    }

注:本文整理自网络!!!

原文地址:https://www.cnblogs.com/YuanSong/p/2618022.html