When the user successfully login, i'm storing the username in tempdata so i can use it in my _Layout:
TempData["username"] = model.Email.Split('@')[0];
TempData.Keep("username");
on my _Layout:
<li class="nav-item">
<h5 style="color:white"> Welcome, @TempData["username"]</h5>
</li>
this actually works on the first load, but if I go to another page, the tempdata turns to null and no username is displaying. How can i keep the username on my _layout?
Tempdata keep method work only for next request. If you want to store data in over all pages. Use MVC identity principal methodology to persist data overall page. Iprincipal
If you've recently changed your authentication to azure Ad and your application is load balanced. Please make sure, you've updated the load balancer to use sticky session. Without a sticky session, the response can come from any server which can result in null temp data.
TempData is designed to have a life span only in between the current and the next request. You'd have to re-store it on every request (or call .Keep()) to make it available on the subsequent request.
You would be better of using a Session object or retrieving it from your user identity.
However you can "keep" your TempData object, if you call .Keep() after calling it (displaying counts towards calling).
<li class="nav-item">
<h5 style="color:white"> Welcome, @TempData["username"]</h5>
@TempData.Keep("username")
</li>
Yet another way to circumvent this, is to use .Peek():
<li class="nav-item">
<h5 style="color:white"> Welcome, @TempData.Peek("username").ToString()</h5>
</li>
