/// <summary>
        /// 验证WinRar是否安装。
        /// </summary>
        /// <returns>true：已安装，false：未安装</returns>
        private static bool ExistsRar(out String winRarPath)
        {
            winRarPath = String.Empty;

            //通过Regedit（注册表）找到WinRar文件 
            var registryKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\WinRAR.exe");

            if (registryKey == null) return false;//未安装

            //registryKey = theReg;可以直接返回Registry对象供会面操作
            winRarPath = registryKey.GetValue("").ToString();//这里为节约资源，直接返回路径，反正下面也没用到

            registryKey.Close();//关闭注册表

            return !String.IsNullOrEmpty(winRarPath);
        }


//csharp/5821