public async Task When_Collection_Reset()
{
var count = 0;
var panel = new StackPanel();
var SUT = new ItemsControl()
{
ItemsPanelRoot = panel,
ItemContainerStyle = BuildBasicContainerStyle(),
InternalItemsPanelRoot = panel,
ItemTemplate = new DataTemplate(() =>
{
count++;
return(new Border());
})
};
SUT.ApplyTemplate();
var c = new ObservableCollectionEx <string>();
c.Add("One");
c.Add("Two");
c.Add("Three");
SUT.ItemsSource = c;
Assert.AreEqual(count, 3);
Assert.AreEqual(SUT.Items.Count, 3);
using (c.BatchUpdate())
{
c.Add("Four");
c.Add("Five");
}
Assert.AreEqual(SUT.Items.Count, 5);
Assert.AreEqual(count, 5);
Assert.IsNotNull(SUT.ContainerFromItem("One"));
Assert.IsNotNull(SUT.ContainerFromItem("Four"));
Assert.IsNotNull(SUT.ContainerFromItem("Five"));
}
