WPF: ComboBox only refreshes to binding when never opened

I have a combobox and set the itemssource to a list of strings:

private List<string> list = new List<string>();
...
ComboBox cbo = new ComboBox();
cbo.ItemsSource = list;

The combobox gets filled successful on startup.

But when the list is changed, the combobox doesn't update its items, BUT only when I expanded the items before, else the combobox gets updated...

Also weird: when I trace the count of items of the combobox, the count is the correct updated number, but the开发者_Go百科 displayed items aren't.

Somebody has an idea, what's going on here?

EDIT: See solution in comments to post of Robert

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I guess you need to use ObservableCollection instead of List, because ComboBox needs to be notified whenever the collecion changes.

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Change List into ObservableCollection.

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Use ObservalbeCollection. It has inbuilt mechanism to notify and change in the number of items.