C# compression and decompression helper class

using System;  
using System.Collections.Generic;  
using System.IO;  
using System.Linq;  
using System.Web;  
using ICSharpCode.SharpZipLib.Zip;  
   
namespace GzRMIS.Main.Business  
{  
    public class ZipHelper  
    {  
        /// <summary>  
        /// 存放待压缩的文件的绝对路径  
        /// </summary>  
        private List<string> AbsolutePaths { set; get; }  
        public string errorMsg { set; get; }  
   
        public ZipHelper()  
        {  
            errorMsg = "";  
            AbsolutePaths = new List<string>();  
        }  
        /// <summary>  
        /// 添加压缩文件或文件夹  
        /// </summary>  
        /// <param name="_fileAbsolutePath">文件或文件夹的绝对路径</param>  
        public void AddFile(string _fileAbsolutePath)  
        {  
            AbsolutePaths.Add(_fileAbsolutePath);  
        }  
        /// <summary>  
        /// 压缩文件或者文件夹  
        /// </summary>  
        /// <param name="_depositPath">压缩后文件的存放路径   如C:\\windows\abc.zip</param>  
        ///  <param name="_Level">压缩级别0~9，数字越大压缩率越高，默认为5</param>  
        /// <returns></returns>  
        public bool CompressionZip(string _depositPath,int _Level=5)  
        {  
            bool result = true;  
            FileStream fs = null;  
            try 
            {  
                ZipOutputStream ComStream = new ZipOutputStream(File.Create(_depositPath));  
                ComStream.SetLevel(_Level);      //压缩等级  
                foreach (string path in AbsolutePaths)  
                {  
                    //如果是目录  
                    if (Directory.Exists(path))  
                    {  
                        ZipFloder(path, ComStream, path);  
                    }  
                    else if (File.Exists(path))//如果是文件  
                    {  
                        fs = File.OpenRead(path);  
                        byte[] bts = new byte[fs.Length];  
                        fs.Read(bts, 0, bts.Length);  
                        ZipEntry ze = new ZipEntry(new FileInfo(path).Name);  
                        ComStream.PutNextEntry(ze);             //为压缩文件流提供一个容器  
                        ComStream.Write(bts, 0, bts.Length);  //写入字节  
                    }  
                }  
                ComStream.Finish(); // 结束压缩  
                ComStream.Close();  
            }  
            catch (Exception ex)  
            {  
                if (fs != null)  
                {  
                    fs.Close();  
                }  
                errorMsg = ex.Message;  
                result = false;  
            }  
            return result;  
        }  
        //压缩文件夹  
        private void ZipFloder(string _OfloderPath, ZipOutputStream zos, string _floderPath)  
        {  
            foreach (FileSystemInfo item in new DirectoryInfo(_floderPath).GetFileSystemInfos())  
            {  
                if (Directory.Exists(item.FullName))  
                {  
                    ZipFloder(_OfloderPath, zos, item.FullName);  
                }  
                else if (File.Exists(item.FullName))//如果是文件  
                {  
                    DirectoryInfo ODir = new DirectoryInfo(_OfloderPath);  
                    string fullName2 = new FileInfo(item.FullName).FullName;  
                    string path = ODir.Name + fullName2.Substring(ODir.FullName.Length, fullName2.Length - ODir.FullName.Length);//获取相对目录  
                    FileStream fs = File.OpenRead(fullName2);  
                    byte[] bts = new byte[fs.Length];  
                    fs.Read(bts, 0, bts.Length);  
                    ZipEntry ze = new ZipEntry(path);  
                    zos.PutNextEntry(ze);             //为压缩文件流提供一个容器  
                    zos.Write(bts, 0, bts.Length);  //写入字节  
                }  
            }  
        }  
        /// <summary>  
        /// 解压  
        /// </summary>  
        /// <param name="_depositPath">压缩文件路径</param>  
        /// <param name="_floderPath">解压的路径</param>  
        /// <returns></returns>  
        public bool DeCompressionZip(string _depositPath, string _floderPath)  
        {  
            bool result = true;  
            FileStream fs = null;  
            try 
            {  
                ZipInputStream InpStream = new ZipInputStream(File.OpenRead(_depositPath));  
                ZipEntry ze = InpStream.GetNextEntry();//获取压缩文件中的每一个文件  
                Directory.CreateDirectory(_floderPath);//创建解压文件夹  
                while (ze != null)//如果解压完ze则是null  
                {  
                    if (ze.IsFile)//压缩zipINputStream里面存的都是文件。带文件夹的文件名字是文件夹\\文件名  
                    {  
                        string[] strs = ze.Name.Split(&#39;\\&#39;);//如果文件名中包含’\\‘则表明有文件夹  
                        if (strs.Length > 1)  
                        {  
                            //两层循环用于一层一层创建文件夹  
                            for (int i = 0; i < strs.Length - 1; i++)  
                            {  
                                string floderPath = _floderPath;  
                                for (int j = 0; j < i; j++)  
                                {  
                                    floderPath = floderPath + "\\" + strs[j];  
                                }  
                                floderPath = floderPath + "\\" + strs[i];  
                                Directory.CreateDirectory(floderPath);  
                            }  
                        }  
                        fs = new FileStream(_floderPath + "\\" + ze.Name, FileMode.OpenOrCreate, FileAccess.Write);//创建文件  
                        //循环读取文件到文件流中  
                        while (true)  
                        {  
                            byte[] bts = new byte[1024];  
                            int i = InpStream.Read(bts, 0, bts.Length);  
                            if (i > 0)  
                            {  
                                fs.Write(bts, 0, i);  
                            }  
                            else 
                            {  
                                fs.Flush();  
                                fs.Close();  
                                break;  
                            }  
                        }  
                    }  
                    ze = InpStream.GetNextEntry();  
                }  
            }  
            catch (Exception ex)  
            {  
                if (fs != null)  
                {  
                    fs.Close();  
                }  
                errorMsg = ex.Message;  
                result = false;  
            }  
            return result;  
        }  
   
    }  
}