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如何更改SelectedItem(在列表框中)的颜色?

uwp-xaml uwp xaml c#

tayabuz · 技术社区 · 7 年前

下面是一个列表框

<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问题。答案- List<string> 。需要更改列表框单击处理程序中所选项目的颜色。现在处理程序代码如下所示:

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);
    }

}

这种方法的问题是,应用程序中的每个地方的颜色都会发生变化。要使SelectedItem的颜色仅在此列表框中更改,有什么必要?

1 回复 | 直到 7 年前

Michael Hawker - MSFT 7 年前

您正在修改 Application.Current.Resources ,这将影响所有ListView。改为更改控件实例上的资源:

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);
    }

}

每一个 FrameworkElement 可以拥有自己的资源,在访问父元素(如页面或应用程序)以查找合适的源之前,将首先查看这些资源。