Home/ Questions/Q 961125
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T01:17:32+00:00

I plan to create a typical Master-Detail scenario, i.e. a collection of items displayed

  • 0

I plan to create a typical Master-Detail scenario, i.e. a collection of items displayed in a ListView via DataBinding to an ICollectionView, and details about the selected item in a separate group of controls (TextBoxes, NumUpDowns…).

No problem so far, actually I have already implemented a pretty similar scenario in an older project. However, it should be possible to select multiple items in the ListView and get the appropriate shared values displayed in the detail view. This means, if all selected items have the same value for a property, this value should be displayed in the detail view. If they do not share the same value, the corresponding control should provide some visual clue for the user indicating this, and no value should be displayed (or an “undefined” state in a CheckBox for example). Now, if the user edits the value, this change should be applied to all selected items.

Further requirements are:

  • MVVM compatibility (i.e. not too much code-behind)
  • Extendability (new properties/types can be added later on)

Does anyone have experience with such a scenario? Actually, I think this should be a very common scenario. However, I could not find any details on that topic anywhere.

Thanks!
gehho.

PS: In the older project mentioned above, I had a solution using a subclass of the ViewModel which handles the special case of multi-selection. It checked all selected items for equality and returned the appropriate values. However, this approach had some drawbacks and somehow seemed like a hack because (besides other smelly things) it was necessary to break the synchronization between the ListView and the detail view and handle it manually.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    In your ViewModel, create a property that will bind to your ListView’s SelectedItems.

    Create another property that will represent the details object of your selected items.

    The details section (in the XAML) is binding to this details property (in the ViewModel).

    Every time selected items collection is modified (setter/CollectionChanged event), you need to update your details object as well (that will iterate through the relevant properties and decide if they’re of the same value or not).

    Once a property in the details object is modified, you need to iterate back on your selected items collection and make the relevant changes on them.

    That’s it.

    Hope it helps

    • 0