C#：文件操作

• DriveInfo 获取驱动器信息

        //获取驱动器信息
        void GetDriveInfo()
        {
            DriveInfo driveInfo = new DriveInfo("C");
            Console.WriteLine("驱动器的名称：" + driveInfo.Name);
            Console.WriteLine("驱动器类型：" + driveInfo.DriveType);
            Console.WriteLine("驱动器可用空间大小：" + driveInfo.TotalFreeSpace / Math.Pow(1024, 3) + "G");
            Console.WriteLine("驱动器总大小：" + driveInfo.TotalSize / Math.Pow(1024, 3) + "G");
        }
        //获取所有驱动器
        void GetDrivesInfos()
        {
            DriveInfo[] driveInfos = DriveInfo.GetDrives();
            foreach(DriveInfo info in driveInfos)
            {
                Console.WriteLine("驱动器名称：" + info.Name);
                Console.WriteLine("驱动器文件格式：" + info.DriveFormat);
            }
        }

• Directory 文件夹操作

        void CreateDirectory()
        {
            //如果存在就删除文件夹，不存在就创建
            if (Directory.Exists("D:\\code"))
            {
                Directory.Delete("D:\\code", true);
            }
            else
            {
                Directory.CreateDirectory("D:\\code");
            }

            //第二种方式创建文件夹
            DirectoryInfo directoryInfo = new DirectoryInfo("D:\\code");
            directoryInfo.Create();
            //创建子文件夹
            directoryInfo.CreateSubdirectory("code-1");
            //删除文件夹
            directoryInfo.Delete(true);
        }

• File 文件操作

        void CreateFile()
        {
            FileInfo fileInfo = new FileInfo("D:\\code\\test.txt");
            //如果文件不存在则创建文件
            if (!fileInfo.Exists)
            {
                fileInfo.Create().Close();
            }
            //移动文件，如果新目录不存在该文件则可以移动，不加该判断会报错
            FileInfo newfileInfo = new FileInfo("D:\\code\\code-1\\test1.txt");
            if (!newfileInfo.Exists)
            {
                fileInfo.MoveTo("D:\\code\\code-1\\test1.txt");
            }
            //输出文件信息
            Console.WriteLine("文件路径：" + fileInfo.Directory);
            Console.WriteLine("文件名称：" + fileInfo.Name);
            Console.WriteLine("文件是否只读：" + fileInfo.IsReadOnly);
            Console.WriteLine("文件大小：" + fileInfo.Length);
        } 

• StreamReader  读取流

        void Reader()
        {
            string path = @"D:\\code\test.txt";
            StreamReader streamReader = new StreamReader(path);
            //一直读取到文件末尾
            //Peek():获取流中的下一个字符的整数，如果没有获取到字符， 则返回 -1
            while (streamReader.Peek() != -1)
            {
                Console.WriteLine(streamReader.ReadLine());
            }
            //读完之后别忘了关闭文件
            streamReader.Close();
        }

• StreamWrite  写入流

        void WriteToFile()
        {
            string path = @"D:\\code\test.txt";
            StreamWriter streamWrite = new StreamWriter(path);
            //如果已存在该文本，此方法会覆盖
            streamWrite.WriteLine("写入一行");
            //刷新缓存区
            streamWrite.Flush();
            //关闭流
            streamWrite.Close();
        }    

• FileStream  文件流

            //写入
            string path = @"D:\\code\\test.txt";
            FileStream fileStream = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
            string msg = "just test";
            byte[] bytes = Encoding.UTF8.GetBytes(msg);
            fileStream.Write(bytes, 0, bytes.Length);
            fileStream.Flush();
            fileStream.Close();
            //读取
            string path = @"D:\\code\\test.txt";
            FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
            byte[] bytes = new byte[fileStream.Length];
            fileStream.Read(bytes, 0, bytes.Length);
            char[] c = Encoding.UTF8.GetChars(bytes);
            Console.WriteLine(c);
            fileStream.Close();