CODEWITHSUNDEEP
c#xamluwpuwp-xaml
tayabuz
tayabuz

Reputation: 25

How to change the color of SelectedItem (in ListBox)?

There is the following ListBox

<ListBox x: Name = "ListBoxQuestionAnswers" ItemsSource = "{x: Bind Question.Answers}" SelectionMode = "Single" SelectionChanged = "ListBoxQuestionAnswers_OnSelectionChanged">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBlock x: Name = "TextBlockInListBox" TextWrapping = "Wrap" Text = "{Binding}" />
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

Where Question.Answers - List<string>. It is necessary to change the color of the selected item in the ListBox click handler. Now the handler code looks like this:

private void ListBoxQuestionAnswers_OnSelectionChanged (object sender, SelectionChangedEventArgs e)
{
    if (ListBoxQuestionAnswers.SelectedIndex == Question.CorrectAnswerIndex)
    {
        Application.Current.Resources ["SystemControlHighlightListAccentLowBrush"] = new SolidColorBrush (Colors.Green);
        Application.Current.Resources ["SystemControlHighlightListAccentMediumBrush"] = new SolidColorBrush (Colors.Green);
    }
    else
    {
        Application.Current.Resources ["SystemControlHighlightListAccentLowBrush"] = new SolidColorBrush (Colors.Red);
        Application.Current.Resources ["SystemControlHighlightListAccentMediumBrush"] = new SolidColorBrush (Colors.Red);
    }

}

The problem with this method is that the color changes everywhere in the app. What is necessary that SelectedItem's color has changed only in this ListBox?

Upvotes: 2

Views: 305

Answers (1)

Michael Hawker - MSFT
Michael Hawker - MSFT

Reputation: 1580

You're modifying the Application.Current.Resources, which will effect all listviews. Instead change the resources on your control instance instead:

private void ListBoxQuestionAnswers_OnSelectionChanged (object sender, SelectionChangedEventArgs e)
{
    if (ListBoxQuestionAnswers.SelectedIndex == Question.CorrectAnswerIndex)
    {
        ListBoxQuestionAnswers.Resources ["SystemControlHighlightListAccentLowBrush"] = new SolidColorBrush (Colors.Green);
        ListBoxQuestionAnswers.Resources ["SystemControlHighlightListAccentMediumBrush"] = new SolidColorBrush (Colors.Green);
    }
    else
    {
        ListBoxQuestionAnswers.Resources ["SystemControlHighlightListAccentLowBrush"] = new SolidColorBrush (Colors.Red);
        ListBoxQuestionAnswers.Resources ["SystemControlHighlightListAccentMediumBrush"] = new SolidColorBrush (Colors.Red);
    }

}

Every FrameworkElement can have its own resources which will be looked at first before walking up to parent elements (like pages or the app) to look for a suitable source.

Upvotes: 1

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