c# zip压缩类

使用ICSharpCode.SharpZipLib.dll；  
  下载地址  
  http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx 

using System;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;

namespace LogPost
{
	public class ZipClass
	{
		#region 加压
		/// <summary>
		/// 功能：压缩文件（暂时只压缩文件夹下一级目录中的文件，文件夹及其子级被忽略）
		/// </summary>
		/// <param name="dirPath">被压缩的文件夹夹路径</param>
		/// <param name="zipFilePath">生成压缩文件的路径，为空则默认与被压缩文件夹同一级目录，名称为：文件夹名+.zip</param>
		/// <param name="err">出错信息</param>
		/// <returns>是否压缩成功</returns>
		public bool ZipFile(string dirPath, string zipFilePath, out string err)
		{
			err = "";
			if (dirPath == string.Empty)
			{
				err = "要压缩的文件夹不能为空！";
				return false;
			}
			if (!Directory.Exists(dirPath))
			{
				err = "要压缩的文件夹不存在！";
				return false;
			}
			//压缩文件名为空时使用文件夹名＋.zip
			if (zipFilePath == string.Empty)
			{
				if (dirPath.EndsWith("\\"))
				{
					dirPath = dirPath.Substring(0, dirPath.Length - 1);
				}
				zipFilePath = dirPath + ".zip";
			}

			try
			{
				string[] filenames = Directory.GetFiles(dirPath);
				using (ZipOutputStream s = new ZipOutputStream(File.Create(zipFilePath)))
				{
					s.SetLevel(9);
					byte[] buffer = new byte[4096];
					foreach (string file in filenames)
					{
						ZipEntry entry = new ZipEntry(Path.GetFileName(file));
						entry.DateTime = DateTime.Now;
						s.PutNextEntry(entry);
						using (FileStream fs = File.OpenRead(file))
						{
							int sourceBytes;
							do
							{
								sourceBytes = fs.Read(buffer, 0, buffer.Length);
								s.Write(buffer, 0, sourceBytes);
							} while (sourceBytes > 0);
						}
					}
					s.Finish();
					s.Close();
				}
			}
			catch (Exception ex)
			{
				err = ex.Message;
				return false;
			}
			return true;
		}

		#endregion

		#region 解压方法
		/// <summary>
		/// 功能：解压zip格式的文件。
		/// </summary>
		/// <param name="zipFilePath">压缩文件路径</param>
		/// <param name="unZipDir">解压文件存放路径,为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹</param>
		/// <param name="err">出错信息</param>
		/// <returns>解压是否成功</returns>
		public bool UnZipFile(string zipFilePath, string unZipDir, out string err)
		{
			err = "";
			if (zipFilePath == string.Empty)
			{
				err = "压缩文件不能为空！";
				return false;
			}
			if (!File.Exists(zipFilePath))
			{
				err = "压缩文件不存在！";
				return false;
			}
			//解压文件夹为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹
			if (unZipDir == string.Empty)
				unZipDir = zipFilePath.Replace(Path.GetFileName(zipFilePath), Path.GetFileNameWithoutExtension(zipFilePath));
			if (!unZipDir.EndsWith("\\"))
				unZipDir += "\\";
			if (!Directory.Exists(unZipDir))
				Directory.CreateDirectory(unZipDir);

			try
			{
				using (ZipInputStream s = new ZipInputStream(File.OpenRead(zipFilePath)))
				{

					ZipEntry theEntry;
					while ((theEntry = s.GetNextEntry()) != null)
					{
						string directoryName = Path.GetDirectoryName(theEntry.Name);
						string fileName = Path.GetFileName(theEntry.Name);
						if (directoryName.Length > 0)
						{
							Directory.CreateDirectory(unZipDir + directoryName);
						}
						if (!directoryName.EndsWith("\\"))
							directoryName += "\\";
						if (fileName != String.Empty)
						{
							using (FileStream streamWriter = File.Create(unZipDir + theEntry.Name))
							{

								int size = 2048;
								byte[] data = new byte[2048];
								while (true)
								{
									size = s.Read(data, 0, data.Length);
									if (size > 0)
									{
										streamWriter.Write(data, 0, size);
									}
									else
									{
										break;
									}
								}
							}
						}
					}//while
				}
			}
			catch (Exception ex)
			{
				err = ex.Message;
				return false;
			}
			return true;
		}//解压结束
		#endregion
	}
}