Update listview items when datasource changes

Question

I have a list that I use as a log. I want to see the log in a listview therefor I have created:

 <ListView Margin="12,114,12,12" Name="listView1" ItemsSource="{Binding}" IsSynchronizedWithCurrentItem="True" />

The log gets populated with a field on a class that I did not create, so there is a class as:

SomeClass
{

     public ReadOnlyCollection<Status> Log
     {
         get
         {
              return _log.AsReadOnly();
         }
     }

     // other method and fields
     // etc...

}

so I am able to see the list items. Moreover, I am able to populate the listview with this log as:

listView1.DataContext = server.Log;   // server is an instance of SomeClass

the only problem is that every time the log changes the listview does not update. I have to call listView1.DataContext = server.Log; every time I wish to refresh the log.

how can I avoid having to refresh the listview?

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

You need to use an ObservableCollection<Status> instead of a ReadOnlyCollection<Status>

The reason for this is that Observable collection notifies the controls it is bound to whenever an item is added/removed.

If you want each Status object to notify the view when one of their property changes (so a property in a Status instance changes, but there is no add/remove on the collection), then Status has to implement INotifyPropertyChanged, and each Property needs to raise the PropertyChanged event on its setter.

You can do all this via composition also, if it's a third-party dll.

Sidenote: why do you have a Margin above 100? you should use ContentPresenters such as Grid or StackPanels

that class is actually a dll so I am not able to modify it. If I could then I would fire an event every time the log changes.... — Tono Nam, Aug 28 '11 at 17:49

Update listview items when datasource changes

1 Answers1