“System.Configuration.ConfigurationSettings.AppSettings”已过时-请高和解决,该怎么解决

“System.Configuration.ConfigurationSettings.AppSettings”已过时---请高和解决
警告 1 “System.Configuration.ConfigurationSettings.AppSettings”已过时:“This   method   is   obsolete,   it   has   been   replaced   by   System.Configuration!System.Configuration.ConfigurationManager.AppSettings” E:\n\3CMarketY\Mkt3C_Class\MailClass.cs 192 23 Mkt3C_Class


------解决方案--------------------------------------------------------
用他System.Configuration.ConfigurationManager.AppSettings代替啊
------解决方案--------------------------------------------------------
没关系的．

新的方法是：
System.Configuration.ConfigurationManager.AppSettings