c# - Append to Global List -

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i started learning wpf , c#. have global list want append on event.

code:

public partial class mainwindow : window {     public list<user> items = new list<user>();      someeventhandler            {                 items.add(new user() { name = "john", age = 42 });                 listviewusers.itemssource = items;            } }

however, updated first time event fires, , not subsequent events. if move 

public list<user> items = new list<user>();

to someeventhandler, listviewusers show latest update , not previous record. how append items?

although prefer bind in xaml via viewmodel, solve problem, should use observablecollection below. automatically update listview if item added in collection:

    public partial class mainwindow : window     {         public observablecollection<user> items = new observablecollection<user>();          public mainwindow()         {             initializecomponent();             listviewusers.itemssource = items;          }           someeventhandler            {                 items.add(new user() { name = "john", age = 42 });             } }

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