Implementing a login/logout system - windows-phone-7

Question

i have a problem with a WP7 app. I want that a user can login into the application, doing some stuff and logout.
Now, then a new user get the phone, it should not be possible to get into the session of the old user (by simply pressing back until the user see the intern data of the previous user who was logged in).
how to make this?
The best thing would be, that when a user press the back button, it will be forwared to the first page of the app. the problem then is, that there will be a loop and the app will not pass the certification because it will not be possible to exit it.
Here is an overview:
loginPage (no return just exiting the app) -> internPage (possibility to logout and return to loginPage)

Answer 1

You can clear the back stack using NavigationService.RemoveBackEntry:
while (this.NavigationService.BackStack.Any())
{
this.NavigationService.RemoveBackEntry();
}
Put this in the OnNavigatedTo of your LoginPage, so pressing back on this page will exit the application. If the LoginPage is the first page the user sees when launching the app (and therefore is the application main page), it should pass certification.

Answer 2

try the nonlinearnavigationservice that way back will unwind your history properly an you back out of the mainpage it will exit your app correctly.
http://create.msdn.com/en-US/education/catalog/article/nln-serv-wp7
why not have the mainpage show the icons for the different users, and a click onto the user would ask for their password?

Answer 3

You cannot change the navigation flow of your application so that the back-button takes you to the first page. This will result in you failing the marketplace certification.
What you could do is handle the application lifecycle events, when the user leaves your application, then navigates back to it via the back-button you application is re-started either from a dormant or tombstoned state.
You can read about the lifecycle here:
http://www.scottlogic.co.uk/blog/colin/2011/10/a-windows-phone-7-1-mango-mvvm-tombstoning-example/
You need to add logic into the Activated event. At this point you could display a logic Popup that ensures the user has to re-enter their credentials to continue using the application.

Answer 4

The best way is to create separate view like UserControl and then show it as Popup when you need user to log in.
This is the way recommended by Microsoft also, and zou won't be having this navigation problems.
Something like this:
enter link description here