Strange results in AutoSuggestBox in Windows Phone 8.1

Question

I am trying to use the standard AutoSuggestBox in a Windows Phone 8.1 XAML app, but it behaves really strangely.

In a simple demo, I have collection

Items = new ObservableCollection<string>
        {
            "a",
            "b",
            "c",
            "d"
        };

and he AutoSuggestBox in XAML:

<AutoSuggestBox ItemsSource="{Binding Items}" />

The problem is that no matter what I write to the AutoSuggestBox, I always get all the items:

The documentation says next to nothing and I have not found any samples using this control.

Answer 1

Try the following code:

    private void AutoSuggestBox_TextChanged(AutoSuggestBox sender,
        AutoSuggestBoxTextChangedEventArgs args)
    {
            List<string> myList = new List<string>();
            foreach (string myString in PreviouslyDefinedStringArray)
            {
                if (myString.Contains(sender.Text) == true)
                {
                    myList.Add(myString);
                }
            }
            sender.ItemsSource = myList;
    }

This should work on WP 8.1

Answer 2

Based on this blog post, it looks like what you're expecting (automatic filtering) isn't the case - instead, you need to hook into the TextChanged event and populate the Suggestions collection yourself.

From the documentation:

The app is notified when text has been changed by the user and is responsible for providing relevant suggestions for this control to display.