public class LhaUtity
    {
        ///取得DLL的版本
        [DllImport("unlha32")]
        private static extern UInt16 UnlhaGetVersion();

        /// summary>
        /// '取得DLL的执行情况
        /// /summary>
        /// returns>是否成功/returns>
        [DllImport("unlha32")]
        private static extern  Boolean UnlhaGetRunning();

        /// summary>
        /// '文件检查
        /// /summary>
        /// param name="szFileName">/param>
        /// param name="iMode">/param>
        /// returns>/returns>
        [DllImport("unlha32")]
        private static extern Boolean UnlhaCheckArchive(String szFileName, Int32 iMode);

        /// summary>
        /// 文件解压缩
        /// /summary>
        /// param name="hwnd">/param>
        /// param name="szCmdLine">/param>
        /// param name="szOutput">/param>
        /// param name="dwSize">/param>
        /// returns>/returns>
        [DllImport("unlha32")]
        private static extern int Unlha(int hwnd, string szCmdLine, string szOutput, int dwSize);

        /// summary>
        /// 需要解压的文件
        /// /summary>
        /// param name="archiveFile">解压文件路径/param>
        /// param name="extractDir">解压到路径/param>
        /// param name="isDeleteFile">是否删除/param>
        public static bool UnCompress(string archiveFile, string extractDir,bool  isDeleteFile)
        {
            string extractFullPath = string.Empty;
            string startPath = AppDomain.CurrentDomain.BaseDirectory;

            if (!System.IO.File.Exists(archiveFile))
            {
                //判断需要解压的文件存不存
                throw new Exception(string.Format("需要解压的{0}不存在", archiveFile));
            }

            try
            {
                UInt16 ver = LhaUtity.UnlhaGetVersion();
            }
            catch (Exception ex)
            {
                throw new Exception("没找到Unlha32.dll文件");
            }

            if (UnlhaGetRunning())
            {
                throw new Exception("DLL正在执行");
            }

            if (!UnlhaCheckArchive(archiveFile, 0))
            {
                throw new Exception("文件不能被解压缩");
            }

            //解压的路径
            if (string.IsNullOrEmpty(extractDir))
            {
                extractFullPath =string.Format(@"{0}{1}\", startPath,archiveFile.Substring(archiveFile.LastIndexOf("\\")+1,archiveFile.IndexOf(".lha")-1-archiveFile.LastIndexOf("\\")));
            }
            else
            {
                extractFullPath = extractDir;
            }

            if (!System.IO.Directory.Exists(extractFullPath))
            {
                System.IO.Directory.CreateDirectory(extractFullPath);
            }
              

            int ret = Unlha(0, string.Format("x \"{0}\" \"{1}\"", archiveFile, extractFullPath), null, 0);

            if (ret != 0)
            {

                if (ret == 32800)
                {
                    throw new Exception("文件解压缩取消");
                }
                else
                {
                    throw new Exception("文件解压缩异常结束");

                }

            }
            else
            {
                if (isDeleteFile)
                {
                    System.IO.File.Delete(archiveFile);
                }

                return true;
            }

        }

}