I know I can explicitly set and unset a Session manually but I believe this is worth to ask. In c#, there is a dictionary called TempData which stores data until the first r
As @AVD tells, there is no such command. And I can't really see why. The thing with TempData is that it allows you to save some values / objects for a roundtrip to the server.
If you do use Sessions in your website there is no issue to not use Session to store these values. Session storage is placed on the server and the users is identified by a sessionid which is sent to the server each time.
The only performance penalty I can see is if you were to run your session storage outside your process running the http handler. Otherwise they are both in memory and should be pretty fast.