Overriding ListBoxItem background color when not i

2019-04-20 17:05发布

问题:

According to this, overriding the ControlBrushKey resource should change the background color of a ListBox selected item when it doesn't have focus. I created a simple example to disprove this:

 <StackPanel>
    <ListBox>
      <ListBox.Resources>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="LightBlue"/>
        <!--SelectedItem without focus but doesn't really work-->
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Orange" />
      </ListBox.Resources>
      <ListBoxItem>
        Item 1
      </ListBoxItem>
      <ListBoxItem>
        Item 2
      </ListBoxItem>
    </ListBox>
    <TextBox></TextBox>
  </StackPanel>

If you run this in .NET 4.5 you can see that it only changes the in-focus color, but not the not-in-focus (it works in .NET 4.0). Any idea why?

Edit: This seems to be duplicate of List/Combo Box Background And Selected Colours Under .net 4.5.

回答1:

Try the following for changing the selected ListBoxItem's background color when it has lost focus:

XAML

<ListBox.Resources>    
    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="LightBlue"/> 
    <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey }" Color="Orange" />    
</ListBox.Resources>

C#

listBox.Resources.Add(SystemColors.InactiveSelectionHighlightBrushKey, 
                      new SolidColorBrush(Colors.Orange));

I hope it works for you.



回答2:

It's all about the default templates of the controls, if they do not use the system colors as they did in .NET 4 this will simply not change anything.



回答3:

Here's what I came up with that doesn't involve changing system colors or control templates. Simply wrap the ListBox in a new UserControl.

public partial class StyledListBox : UserControl
{
    public DataTemplate ItemTemplate
    {
        get { return (DataTemplate)GetValue(ItemTemplateProperty); }
        set { SetValue(ItemTemplateProperty, value); }
    }

    public IEnumerable ItemsSource
    {
        get { return (IEnumerable)GetValue(ItemsSourceProperty); }
        set { SetValue(ItemsSourceProperty, value); }
    }

    public object SelectedItem
    {
        get { return GetValue(SelectedItemProperty); }
        set { SetValue(SelectedItemProperty, value); }
    }

    public StyledListBox()
    {
        InitializeComponent();
    }

    public static readonly DependencyProperty ItemTemplateProperty = DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(StyledListBox), new FrameworkPropertyMetadata(null));
    public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register("ItemsSource", typeof(IEnumerable), typeof(StyledListBox), new FrameworkPropertyMetadata(null));

    public static readonly DependencyProperty SelectedItemProperty = DependencyProperty.Register("SelectedItem", typeof(object), typeof(StyledListBox), new FrameworkPropertyMetadata(null)
    {
        BindsTwoWayByDefault = true,
        DefaultUpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
    });
}

XAML:

<UserControl x:Class="StyledListBox"

     <ListBox ItemsSource="{Binding ItemsSource, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type common:StyledListBox}}}"
              SelectedItem="{Binding SelectedItem, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type common:StyledListBox}}}">

        <ListBox.ItemTemplate>
            <DataTemplate>
                <Border>
                    <Border.Style>
                        <Style TargetType="{x:Type Border}">
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding IsSelected, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBoxItem}}}"
                                             Value="True">
                                    <Setter Property="Background" Value="Red" />
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </Border.Style>

                    <ContentPresenter ContentTemplate="{Binding ItemTemplate, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type StyledListBox}}}" />
                </Border>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</UserControl>

Then simply use the wrapper UserControl as if it were a ListBox. Any other ListBox properties you want to control can simply be added to the wrapper in the same manner as ItemsSource and SelectedItem from my example.



回答4:

The solution to this is adding

FrameworkCompatibilityPreferences.AreInactiveSelectionHighlightBrushKeysSupported = false;

before calling

InitializeComponent();