创建BaseConfig轻松获取AppSetting

       我们经常存储一些配制信息在AppSettings中，是不是经常要写取它们值的代码。让我们写一个简单的基类吧：

   /// <summary>
    /// BaseWebConfig
    /// </summary>
    public class BaseWebConfig
    {
        #region Methods (6)

        // Protected Methods (6)

        /// <summary>
        /// Gets the app setting.
        /// </summary>
        /// <param name="appSettingName">Name of the app setting.</param>
        /// <returns></returns>
        protected static string GetAppSetting(string appSettingName)
        {
            if (ConfigurationManager.AppSettings[appSettingName] == null)
                throw new NullReferenceException(appSettingName +
                                                 " AppSettings value cannot be null or empty in the web.config.");
            return ConfigurationManager.AppSettings[appSettingName];
        }

        /// <summary>
        /// Gets the bool app setting.
        /// </summary>
        /// <param name="appSettingName">Name of the app setting.</param>
        /// <returns></returns>
        protected static bool GetBoolAppSetting(string appSettingName)
        {
            return Convert.ToBoolean(GetAppSetting(appSettingName));
        }

        /// <summary>
        /// Gets the connection string.
        /// </summary>
        /// <param name="connectionStringName">Name of the connection string.</param>
        /// <returns></returns>
        protected static string GetConnectionString(string connectionStringName)
        {
            if (ConfigurationManager.ConnectionStrings[connectionStringName] == null)
                throw new NullReferenceException(connectionStringName +
                                                 " ConnectionStrings value cannot be null in the web.config.");
            if (String.IsNullOrEmpty(ConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString))
                throw new NullReferenceException(connectionStringName +
                                                 " ConnectionStrings value cannot be null or empty in the web.config.");
            return ConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString;
        }

        /// <summary>
        /// Gets the date time app setting.
        /// </summary>
        /// <param name="appSettingName">Name of the app setting.</param>
        /// <returns></returns>
        protected static DateTime GetDateTimeAppSetting(string appSettingName)
        {
            DateTime dt;
            if (!DateTime.TryParse(GetAppSetting(appSettingName), out dt))
                throw new InvalidCastException(appSettingName + " AppSettings value is an invalid DateTime.");
            return dt;
        }

        /// <summary>
        /// Gets the int app setting.
        /// </summary>
        /// <param name="appSettingName">Name of the app setting.</param>
        /// <returns></returns>
        protected static int GetIntAppSetting(string appSettingName)
        {
            int i;
            if (!int.TryParse(GetAppSetting(appSettingName), out i))
                throw new InvalidCastException(appSettingName + " AppSettings value is an invalid integer.");
            return i;
        }

        /// <summary>
        /// Gets the string array setting.
        /// </summary>
        /// <param name="appSettingName">Name of the app setting.</param>
        /// <returns></returns>
        protected static string[] GetStringArraySetting(string appSettingName)
        {
            string[] values = GetAppSetting(appSettingName).Split(new[] {','});
            return values;
        }

        #endregion Methods
    }

然后如何用呢？看下面的代码：

    public class WebConfig1 : BaseWebConfig
    {
        public static string ReturnEmail
        {
            get { return GetAppSetting("ReturnEmail"); }
        }

        public static bool IsTestEnvironment
        {
            get { return GetBoolAppSetting("IsTestEnvironment"); }
        }

        public static DateTime ShutOffDate
        {
            get { return GetDateTimeAppSetting("ShutOffDate"); }
        }

        public static string DbConnectionString
        {
            get { return GetConnectionString("DbConnectionString"); }
        }
    }

是不是很简单呀。这个代码你可以放到你自己的类库了，更重要是思想，重用的思想。DRY。Don’t repeat yourself.

希望这篇POST对您有帮助。

Author :Petter Liu      http://wintersun.cnblogs.com