C#对文件操作（基本的读写以及压缩和解压）

主要是针对单个文件进行读写操作和压缩操作：用到的主要C#类有FileStream、FileInfo、StreamWrite、StreamRead、GZipStream。

字符数组和字节数组的转换：

  byte[] bytedata = new byte[];
             char[] chardata = new char[];
             try
             {
                 FileStream fs = new FileStream("App.config", FileMode.Open);
                 fs.Seek(, SeekOrigin.Begin);
                 fs.Read(bytedata, , );
             }
             catch (IOException io)
             {
                 Console.WriteLine(io.ToString());
                 Console.ReadKey();
                 return;
             }
             Decoder dc = Encoding.UTF8.GetDecoder();//创建一个解码器用来对二进制数组解码成字符数组
             dc.GetChars(bytedata, , bytedata.Length, chardata, );
             Console.WriteLine(chardata);
             Console.ReadKey();
             byte[] byteData;
             char[] charData;
             try
             {
                 FileStream fs = new FileStream("Log.txt", FileMode.Create);
                 charData = "this is the user first log the software".ToCharArray();
                 Encoder e = Encoding.UTF8.GetEncoder();
                 byteData = new byte[charData.Length];
                 e.GetBytes(charData, , charData.Length, byteData, , true);
                 fs.Seek(, SeekOrigin.End);
                 fs.Write(byteData, , byteData.Length);
             }
             catch (IOException io)
             {
                 Console.WriteLine(io.ToString());
                 Console.ReadKey();
                 return;
             }
             Console.ReadKey();

对文件进行压缩和解压（一单个文件为例）：

 string fileName = "CompressedFile.txt";
             Console.WriteLine("Please input a word and it will repeate 100 times");
             string inputString = Console.ReadLine();
             StringBuilder sourceString = new StringBuilder(inputString.Length * );
             for (int i = ; i < ; i++)
             {
                 sourceString.AppendLine(inputString);
             }
             string sourceCompresses = sourceString.ToString();
             Console.WriteLine("source data's length is {0}", sourceCompresses.Length);
             try
             {
                 CompressedFile(fileName, sourceCompresses);
                 Console.WriteLine("Compressed successfully");
                 FileInfo fileInfo = new FileInfo(fileName);
                 Console.WriteLine("compressed file's length is{0}", fileInfo.Length);
                 string loadCompressed = LoadCompressedFile(fileName);
                 Console.WriteLine(loadCompressed);
             }
             catch (IOException io)
             {
                 Console.WriteLine(io.ToString());
                 Console.ReadKey();
                 return;
             }
             Console.ReadKey();
         }

         private static void CompressedFile(string fileName, string sourceCompress)
         {
             FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write);
             GZipStream gzCompressedFile = new GZipStream(fs, CompressionMode.Compress);
             StreamWriter sw = new StreamWriter(gzCompressedFile,Encoding.UTF8);
             sw.Write(sourceCompress);
             sw.Close();
         }

         private static string LoadCompressedFile(string fileName)
         {
             FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
             GZipStream gzLoadCompressed = new GZipStream(fs, CompressionMode.Decompress);
             StreamReader sr = new StreamReader(gzLoadCompressed,Encoding.UTF8);
             StringBuilder strBuild = new StringBuilder();
             string strReadLine = sr.ReadLine();
             while (!string.IsNullOrEmpty(strReadLine))
             {
                 strBuild.Append(strReadLine);
                 strReadLine = sr.ReadLine();
             }
             return strBuild.ToString();
         }