Website cannot connect to localdb in asp.net through Website Admin Tool in VS15

Question

I am always getting an error as "Could not establish a connection to the database. If you have not yet created the SQL Server database, exit the Web Site Administration tool, use the aspnet_regsql command-line utility to create and configure the database, and then return to this tool to set the provider." I have already created and configured the database but still the problem persists. here below I am sharing my web.config code

<configuration>
  <connectionStrings>
    <clear/>
    <add name="LocalSqlServer" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial catalog=login;Integrated Security=True"
      providerName="System.Data.SqlClient" /> 
  </connectionStrings>
  <appSettings>
    <add key="ValidationSettings:UnobtrusiveValidationMode" value="None"/>
  </appSettings>
    <system.web>
      <roleManager enabled="true" />
      <authentication mode="Forms"></authentication>
       <membership>
            <providers>
              <clear/>
                <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" connectionStringName="LocalSqlServer" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" applicationName="/" requiresUniqueEmail="false" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression=""/>
            </providers>
        </membership>
      <compilation debug="true" targetFramework="4.5.2" />
      <httpRuntime targetFramework="4.5.2" />
    </system.web>

</configuration>

Somewhere I feel I am wrong in connection string,here below i am also sharing my machine.config connection string format code

<connectionStrings>
        <add name="LocalSqlServer" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient"/>
    </connectionStrings>