使用C#2.0进行文件压缩和解压
使用C#2.0进行文件压缩和解压
作者：skyivben.来源：cnblogs 在fcl2.0中增加了system.io.compression命名空间, 用以进行文件压缩和解压操作，如下所示：using System;using System.IO;using System.IO.Compression; namespace Skyiv.Helper{ static class Zip { public static void CompressFile(string sourceFile, string destinationFile) { if (!File.Exists(sourceFile)) throw new FileNotFoundException(); using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read)) { byte [] buffer = new byte[sourceStream.Length]; int checkCounter = sourceStream.Read(buffer, 0, buffer.Length); if (checkCounter != buffer.Length) throw new ApplicationException(); using (FileStream destinationStream = new FileStream(destinationFile, FileMode.OpenOrCreate, FileAccess.Write)) { using (GZipStream compressedStream = new GZipStream(destinationStream, CompressionMode.Compress, true)) { compressedStream.Write(buffer, 0, buffer.Length); } } } } public static void DecompressFile(string sourceFile, string destinationFile) { if (!File.Exists( sourceFile)) throw new FileNotFoundException(); using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open)) { byte [] quartetBuffer = new byte[4]; int position = (int)sourceStream.Length - 4; sourceStream.Position = position; sourceStream.Read(quartetBuffer, 0, 4); sourceStream.Position = 0; int checkLength = BitConverter.ToInt32(quartetBuffer, 0); byte[] buffer = new byte[checkLength 100]; using (GZipStream decompressedStream = new GZipStream(sourceStream, CompressionMode.Decompress, true)) { int total = 0; for (int offset = 0; ; ) { int bytesRead = decompressedStream.Read(buffer, offset, 100); if (bytesRead == 0) break; offset = bytesRead; total = bytesRead; } using (FileStream destinationStream = new FileStream(destinationFile, FileMode.Create)) { destinationStream.Write(buffer, 0, total); destinationStream.Flush(); } } } } }}using System;using System.IO;using Skyiv.Helper; namespace Skyiv.Test{ sealed class TestMain { static void Main() { try { string [] nameList = {"zip.zip", "zip.cs", "zip.txt"}; Zip.CompressFile(nameList[1], nameList[0]); Zip.DecompressFile(nameList[0], nameList[2]); foreach (string name in nameList) { Console.WriteLine("{0,-11}: {1,11:N0} bytes", name, new FileInfo(name).Length); } } catch (Exception ex) { Console.WriteLine(ex.Message); } } }}运行结果如下:zip.zip : 773 byteszip.cs : 2,196 byteszip.txt : 2,196 bytes但是，如果有使用Zip.DecompressFile()方法去解压标准的ZIP文件，就会出现以下错误：GZip 头中的幻数不正确。请确保正在传入 GZip 流。此外，使用Zip.CompressFile()方法也不能将多个文件放入一个ZIP包。看来，FCL2.0还是不能处理标准的ZIP文件，我目前是使用第三方的ICSharpZipLib来处理ZIP文件：
http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx (2005-10-23:10:28)
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