基于ERP程序的公共代码中出现的问题及过度封装

public class ConfigHelper
{
        /// <summary> /// Gets whether the specified path is a valid absolute file path. /// </summary>
        /// <param name="path">Any path. OK if null or empty.</param>
        static public bool IsValidPath(string path)
        {
            Regex r = new Regex(@"^(([a-zA-Z]:)|(\))(\{1}|((\{1})[^\]([^/:?<>""|]))+)$");
            return r.IsMatch(path);
        }

        public static string GetString(string key)
        {
            return System.Configuration.ConfigurationManager.AppSettings[key];
        }
}

public static decimal GetDecimal(string key)
{
            decimal value = default(decimal);
            if ((decimal.TryParse(GetString(key), out value)))
            {
                return value;
            }
            else
            {
                return 0m;
            }
}