title: How can i get and use AspnetUsers UserId in migration configuration file?
body: <p>This is the code of configuration file(seed method) of entity framework migration. 
  Through this code, i create a user and role for AspnetUsers table and i put the user in role named Admin. </p>
  
  <pre><code>AppUserManager userMgr = new AppUserManager(new UserStore&lt;AppUser&gt;(context));
          AppRoleManager roleMgr = new AppRoleManager(new RoleStore&lt;AppRole&gt;(context));
          string roleName = "Admin";
          string userName = "admin@educationboard.com";
          string password = "Sifre";
          string email = "admin@educationboard.com";
          if (!roleMgr.RoleExists(roleName))
          {
              roleMgr.Create(new AppRole(roleName));
          }
          AppUser user = userMgr.FindByName(userName);
          if (user == null)
          {
              userMgr.Create(new AppUser { UserName = userName, Email = email },
              password);
              user = userMgr.FindByName(userName);
          }
          if (!userMgr.IsInRole(user.Id, roleName))
          {
              userMgr.AddToRole(user.Id, roleName);
          }
          foreach (AppUser dbUser in userMgr.Users)
          {
              dbUser.Cinsiyet = eCinsiyetler.Erkek;
          }
          context.SaveChanges();
  </code></pre>
  
  <p>Then i also create an entity named Articles, each article has an author id. I named AuthorId as UserId in Article entity. How can i get and use UserId I've just created above  in following code?</p>
  
  <pre><code>var articles= new List&lt;Article&gt;
          {
              new Article{Title="Title 1", AddedDate=DateTime.Now,  Content="content here.",  UserId=.(What code should be here? }; 
  articles.ForEach(p =&gt; context.Articles.AddOrUpdate(s =&gt; s.Title, p));
          context.SaveChanges();
  </code></pre>