protected override void OnPreviewKeyUp(KeyEventArgs e)
{
base.OnPreviewKeyUp(e);
if (_suggenstionListBox == null || Keyboard.FocusedElement != this)
{
return;
}
if (e.Key == Key.Down)
{
if (_suggenstionListBox.Items.Count > 0)
{
_suggenstionListBox.SelectedIndex = 0;
var item = _suggenstionListBox.Items[0] as ListBoxItem;
item.IsSelected = true;
_popup.Child.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
}
return;
}
else if (e.Key == Key.Tab && _suggenstionListBox.SelectedIndex > -1)
{
this.Text = ((ListBoxItem)_suggenstionListBox.SelectedItem).Content.ToString();
_suggenstionListBox.Visibility = Visibility.Collapsed;
this.SelectionStart = this.Text.Length;
return;
}
_suggenstionListBox.Items.Clear();
var queryText = this.Text;
if (this.SelectedText.Length > 0 && this.Text.Length > 0)
{
queryText = this.Text.Replace(this.SelectedText, "");
}
var request = new SearchBoxSuggestionsRequestedEventArgs(queryText);
this.OnSuggestionsRequested(request);
int i = 0;
foreach (var suggestion in request.Request.SearchSuggestionCollection)
{
_suggenstionListBox.Items.Add(new ListBoxItem()
{
Content = suggestion
});
i++;
if (i == this.MaxDropDownItems)
{
break;
}
}
this.IsDropDownOpen = (_suggenstionListBox.Items.Count > 0);
_suggenstionListBox.Visibility = (_suggenstionListBox.Items.Count > 0) ? Visibility.Visible : Visibility.Collapsed;
_suggenstionListBox.SelectedIndex = (_suggenstionListBox.Items.Count > 0) ? 0 : -1;
}
private void OnSuggestionsRequested(SearchBoxSuggestionsRequestedEventArgs e)
{
if (this.SuggestionsList != null)
{
if (string.IsNullOrWhiteSpace(e.QueryText))
{
return;
}
var queryText = e.QueryText.ToLower();
foreach (var suggestion in this.SuggestionsList)
{
if (suggestion.ToLower().StartsWith(queryText) &&
suggestion.ToLower() != queryText)
{
e.Request.SearchSuggestionCollection.AppendQuerySuggestion(suggestion);
}
}
}
else if (SuggestionsRequested != null)
{
SuggestionsRequested(this, e);
}
}