在切换到其他控件之前，如何在用户控件上保存数据？

Question

I have a WPF Application with different user controls. Each of them can be accessed by clicking a button on the left side. My issue is, when I am in one of the user controls and filling out the data in textboxes, combo boxes etc, I may have to stop it mid way and click on another user control. While doing that, I need to keep the data in the previous user control intact so that when I return to the first user control, the data should be present in all the controls before I left it. How do I achieve this? Here's a sample picture of how my application looks like:

Picture Credit: https://rachel53461.wordpress.com/2011/12/18/navigation-with-mvvm-2/

From the picture, if I am in the Products Page, I might have several text boxes with data entered in there. For a variety of reasons, I may have to step away from this and click on Home Page or some other page , do some work there and return back to the Products page. When I return, I need the data to be present as is when I left it.

Thanks in Advance

Answer 1

You must have create a ViewModel to each diferent user control. ViewModel remains in memory until you process that or make a diferent process. For Example you hava a User control for your Main Page, that's mean you have a view (MainPageView) of your user control for your main page, that view belong to a ViewModelMainPage. For Products you maybe have a ProductView, that's belong to ViewModelProducts. You must create a ManagerViewModel to manage the view for diferents user control.