Push on a ComboBox using WPF MVVM

Question

I have a combobox in a WPF Window, it is filled with usernames from database,

When a new user is created in database, i want the UserName to be pushed to the ComboBox, ie, added to the existing.

Similary when a User is deleted, it should be Poped from the ComboBox .

How can i do this. Currently, i am using WPF MVVM with Caliburn Micro .

Answer 1

I bind the ItemsSource to an ObservableCollection for that. Works when you add or delete items from the collection.

Answer 2

If you're using MVVM then you should have some collection that is bound to ComboBox.ItemsSource property. If any changes to collection were made - invoke FireProeprtyChanged("UsersCollection") . UI should reflect on this and update ComboBox .

Update:
If you want to provide some kind of push notifications - you have to create HTTP Polling Duplex WCF Service. Nice example of its implementation by Dan Wahlin: Syncing Data with a Server using Silverlight and HTTP Polling Duplex