是因为web.config没写对 , 应该加上这段
<system.web> <compilation debug="true" targetFramework="4.0" /> <authentication mode="Forms"> <forms loginUrl="~/Account/Login.aspx" timeout="2880" /> </authentication> <membership> <providers> <clear /> <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" /> </providers> </membership> </system.web>