C#解压缩

/// <summary>  
        /// 解压缩文件(压缩文件中含有子目录)  
        /// </summary>  
        /// <param name="zipfilepath">待解压缩的文件路径</param>  
        /// <param name="unzippath">解压缩到指定目录</param>  
        /// <returns>解压后的文件列表</returns>  
        public List<string> UnZip(string zipfilepath, string unzippath)
        {
            //解压出来的文件列表  
            List<string> unzipFiles = new List<string>();

            //检查输出目录是否以“\\”结尾  
            if (unzippath.EndsWith("\\") == false || unzippath.EndsWith(":\\") == false)
            {
                unzippath += "\\";
            }

            ZipInputStream s = new ZipInputStream(File.OpenRead(zipfilepath));
            ZipEntry theEntry;
            while ((theEntry = s.GetNextEntry()) != null)
            {
                string directoryName = Path.GetDirectoryName(unzippath);
                string fileName = Path.GetFileName(theEntry.Name);

                //生成解压目录【用户解压到硬盘根目录时，不需要创建】  
                if (!string.IsNullOrEmpty(directoryName))
                {
                    Directory.CreateDirectory(directoryName);
                }

                if (fileName != String.Empty)
                {
                    //如果文件的压缩后大小为0那么说明这个文件是空的,因此不需要进行读出写入  
                    if (theEntry.CompressedSize == 0)
                        continue;
                    //解压文件到指定的目录  
                    directoryName = Path.GetDirectoryName(unzippath + theEntry.Name);
                    //建立下面的目录和子目录  
                    Directory.CreateDirectory(directoryName);

                    //记录导出的文件  
                    unzipFiles.Add(unzippath + theEntry.Name);

                    FileStream streamWriter = File.Create(unzippath + 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;
                        }
                    }
                    streamWriter.Close();
                }
            }
            s.Close();
            GC.Collect();
            return unzipFiles;
        }