using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;

using System.Reflection;
using System.Web;
using System.Windows.Forms;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip;



namespace OnlineUpdate
{
    internal class ZipArchive
    {
        /// <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 static void UnZip(string zipFilePath, string unZipDir)
        {
            try
            {
                if (zipFilePath == string.Empty)
                {
                    throw new Exception("压缩文件不能为空！");
                }
                if (!File.Exists(zipFilePath))
                {
                    throw new System.IO.FileNotFoundException("压缩文件不存在！");
                }
                //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);

                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)
                        {
                            if (theEntry.Name == "OnlineUpdate.exe") continue;
                            using (FileStream streamWriter = File.Create(unZipDir + theEntry.Name))
                            {

                                int size = 5048;
                                byte[] data = new byte[size];
                                while (true)
                                {
                                    size = s.Read(data, 0, data.Length);
                                    if (size > 0)
                                    {
                                        streamWriter.Write(data, 0, size);
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            { }
        }
    }
}