Custom property dependant on other properties

Advance apologies for the event-style explanation; there's a lot of factors that I feel all play a role of their own. WPF is not my native framework of choice, and it probably shows. :)

Old situation: I had a window with several controls. Depending on their selections, I used multibindings and a converter to determine whether certain controls needed to be shown that inform the user about the implications of their changes before they'd eventually confirm them by OK (or simply dismissed by using Cancel). This worked perfectly.

Problem: Too many controls as time went by, too much clutter. Solution: Put stuff in different Pages so it becomes easier to browse for the user. In order to have changes-to-be persist as a user arbitrarily browses between the pages, I create these dynamically and put them in a cache (Dictionary<string, BasePage>, see below), from which they will be pulled as the user chooses them.

Consequence: I need to decouple the bindings to the notification controls as the different options are now on different pages.

Solution? I put a BasePage class in that exposes certain abstract read-only properties that define the various aspects that the window needs to know about in order to do its notifications. For example, a bool requiresReboot property defines whether the current state of things on that page requires a reboot to take (full) effect. A specific page implements the property based on its controls. Problem: I do not know how to keep create a proper binding that properly gets updated as the pages are changed. I tried giving my notification controls a binding to the Dictionary<string, BasePage> with a converter that checks all pages and the relevant property.

Questions:

1) How do I create a proper property for this purpose? I presume I need a DependancyProperty as I did a fair bit of reading on MSDN, but I can开发者_开发问答't figure out how this fits together. 2) How do I make a link between my custom property so that it allows (multiple) control(s) on a page to change that property? Do I use INotifyPropertyChanged somehow? My old example bound against several CheckBox.IsChecked properties in XAML. I am trying to avoid putting tons of events (OnChange, etc) on the controls as the original code did not need it and I have been told it makes for a messy solution for as far WPF is concerned. 3) Finally, I suspect I may need to change my Dictionary<string, BasePage> class to a custom implementation that implements some sort of INotifyPropertyChanged but for Collections? Observable Collection is the term I am looking for, I believe.

I hope someone is able to bridge the gap in my understanding of WPF (property) internals; I would very much appreciate it. A basic sample would be even better, but if it is too complicated, just a nudge in the right direction will do. Thank you. :)

It's been a while since I solved this, and while I cannot remember the exact cause of the problems, there were a few different issues that made up the bulk of the trouble I ran into.

1. I ended up making the Property in question a non-abstract DependencyProperty in the base class; it was the only way in which I could properly delegate the change notifications to the interface. Derived classes simply ended up binding it to their controls (with a proper Converter in the case extra logic was necessitated).

2. As Dictionary<string, BasePage> does not support any sort of change notification, I made an extra collection of ObservableCollection<BasePage> which I used for binding purposes.

3. However, such a collection does not propagate a change event when items inside of it has a property changed. Since this situation required that, and I was binding to the collection itself in the context of a property that does not have a Master<->Detail relationship like a DataGrid (which basically add their own OnPropertyChanged handlers to the binded object), I ended up subclassing a VeryObservableCollecton<>. This one listens to its own items, and throws a proper change event (I think it was an OnPropertyChanged from the INotifyPropertyChanged interface) so that the binding (or in this case a multi-binding) would refresh properly and allow my interface to update.

It is hardly the prettiest code, and it feels over-engineered, but at least it allows me to properly bind the UI to the data in this manner.