注冊表Regedit讀寫

需要引入命名空間：
using Microsoft.Win32;
       /// 讀注冊表中指定鍵的值
        /// </summary>
        /// <param name="key">鍵名</param>
        /// <returns>返回鍵值</returns>
        public static string ReadReg(string key)
        {
            string temp = "";
            try
            {
                RegistryKey key = Registry.LocalMachine;                      //Registry參數自己選擇
                RegistryKey subKey = Key.OpenSubKey("SOFTWARE\Exobo");      //注冊表位置
                temp = subKey.GetValue(key).ToString();
                subKey.Close();
                key .Close();
                return temp;
            }
            catch (Exception)
            {
                throw;
            }
        }
       /// <summary>
        /// 創建目錄(第一次注冊)---寫入
       /// </summary>
       /// <param name="username"></param>
       /// <param name="password"></param>
       /// <param name="userType">版本類型</param>
       /// <param name="userMax">最大試用次數</param>
       /// <param name="userTime">當前試用次數</param>
       /// <returns></returns>
        public static bool CreateReg(string username,string password,string userType,string userMax,string userTime)
        {
            bool temp = false;
            try
            {
                RegistryKey Key = Registry.LocalMachine;
                RegistryKey subKey = Key.OpenSubKey(@"SOFTWAREExobo");
                //未注冊 從新創建
                if (subKey == null)
                {
                    Key.CreateSubKey("SOFTWARE\Exobo");
                }
              //修改注冊信息
                subKey = Key.OpenSubKey("SOFTWARE\Exobo", true);
                subKey.SetValue(username, password);
                subKey.SetValue(username + "Type", userType);
                subKey.SetValue(username + "Time", userTime);
                subKey.SetValue(username + "Max", userMax);             
                temp = true;
                subKey.Close();
                Key.Close();
                return temp;

            }
            catch (Exception)
            {
                throw;
            }

        }
   //判段是否有該項
        public static bool HaveReg()
        {
            bool temp = false;
            try
            {
                RegistryKey Key = Registry.LocalMachine;
                RegistryKey subKey = Key.OpenSubKey(@"SOFTWAREExobo");
                //未注冊 從新創建
                if (subKey == null)
                {
                    temp = false;
                }
                else
                {
                    temp = true;