在web.config文件中，未定义<globalization fileEncoding="utf-8" requestEncoding="utf-8" responseEncoding="gb2312"/>,将此定义在<system.web></system.web>中，问题解决。
<?xml version="1.0"?>
<configuration><connectionStrings>
<add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.0" />
<globalization fileEncoding="utf-8" requestEncoding="utf-8" responseEncoding="gb2312"/>
<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>
<profile>
<providers>
<clear/>
<add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/>
</providers></profile>
<roleManager enabled="false">
<providers>
<clear/>
<add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
<add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
</providers>
</roleManager>
</system.web>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
</configuration>