未配置匿名登录 userIdentity 不应为空

如何解决未配置匿名登录 userIdentity 不应为空

public void GetUserInfo(out IIdentity userIdentity,out IntPtr userId) {

        if (HttpContext.Current != null
              && HttpContext.Current.User != null)
        {
            userIdentity = HttpContext.Current.User.Identity;
          
        }
        else
        {
         
         throw new NullReferenceException("Anonymous logon is not configured. 
          userIdentity should not be null!");
        }

        // initialize a pointer to the current user id to zero
        userId = IntPtr.Zero;
    }

HttpContext.Current.User.Identity 即将为空。