How do you safely update collections bound to the UI from background threads?

Marshal collection mutations to the UI thread, since CollectionView observes changes on the UI thread. Compute/fetch data in the background, then add items via MainThread.BeginInvokeOnMainThread, or gather results and assign once. Some toolkit collections offer thread-safe patterns, but explicit marshaling is safest.

var page = await _api.GetPageAsync();
MainThread.BeginInvokeOnMainThread(() =>
{
    foreach (var item in page) Items.Add(item);
});