ASP.NET:如何检测身份验证超时

 <system.web>
   <sessionState timeout="20"></sessionState>
  </system.web>
</configuration>

 <system.web>
   <authentication mode="Forms">
     <forms timeout="20"></forms>
    </authentication>
  </system.web>
</configuration>

 <system.identityModel.services>
    <federationConfiguration>
      <wsFederation passiveRedirectEnabled="true" issuer="http://localhost:5000/identity" realm="http://localhost:5000/" reply="http://localhost:5000/" requireHttps="false" />
     <cookieHandler requireSsl="false" persistentSessionLifetime="0.00:20:00" />
    </federationConfiguration>
  </system.identityModel.services>
</configuration>

public void Configuration(IAppBuilder app)
{
    GlobalHost.Configuration.ConnectionTimeout = TimeSpan.FromSeconds(30);
    app.MapSignalR();
}