WPF ListView Keyboard Navigation Problem

Question

I've a listview like this

ListView:
————-----

• Mango
• Orange
• Grapes
• Grapes
• Grapes
• Apple
• Strawberry

---

Whenever i navigate using downarrow, the BlueHighlight pauses at the first Grapes, a dotted rectangle start from second grapes and pauses at the third grapes, then the BlueHighlight resumes from Apple. This seems weird and it grows more weird when the navigation is upwards. It jumps from Apple to Orange or mango.

Is this due to Virtualization?
It seems only the duplicate data (grapes) is creating the problem. Any Help?

Answer 1

You have the same "Grapes" object in ObservableCollection 3 times, I mean the object with same reference. And Listbox is mess with this. Each element should be an uncial instance.

Answer 2

Think of the blue highlight as the selected data item. Grapes is duplicated, so the data selection doesn't change.

The dotted rectangle is the keyboard focus, which only cares about the ListViewItem that represents the data item.

So there's one Grapes object represented by 3 ListViewItem objects.

Answer 3

The dotted rectangle is your keyboard focus. The blue rectangle is your selection.

As you move down your keyboard focus tracks where you are. The selection, however, tracks which item is selected. When the same item is in the list several times, the selection rectangle can only be shown on one of them.

To make this work the way you are expecting, wrap your items inside your ObservableCollection. So instead of:

coll.Add(fruit);

you would write

coll.Add(new FruitWrapper(fruit));

In your ListBox your ItemTemplate can include a single ContentPresenter that presents the fruit inside the wrapper (eg. <ContentPresenter Content="{Binding Fruit}" />).