WPF TreeView：如何像在资源管理器中一样使用圆角设置所选项目的样式

Question

WPF TreeView 中的所选项目具有带有“尖”角的深蓝色背景。今天看起来有点过时：

我想将背景更改为在资源管理器中的样子Windows 7 的（有/无焦点）：

到目前为止我所尝试的并没有删除原始的深蓝色背景，而是在其顶部绘制了一个圆形边框，以便您在边缘看到深蓝色，并且在左边-丑陋。

有趣的是，当我的版本没有焦点时，它看起来还不错：

我不想将控件模板重新定义为 显示此处或此处。我想设置最少必需的属性，以使所选项目看起来像在资源管理器中。

替代方案：我也很高兴让焦点选定的项目看起来像我现在没有焦点时的样子。失去焦点时，颜色应从蓝色变为灰色。

这是我的代码：

<TreeView 
    x:Name="TreeView"
    ItemsSource="{Binding TopLevelNodes}" 
    VirtualizingStackPanel.IsVirtualizing="True"
    VirtualizingStackPanel.VirtualizationMode="Recycling">

    <TreeView.ItemContainerStyle>
        <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />

            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="BorderBrush" Value="#FF7DA2CE" />
                    <Setter Property="Background" Value="#FFCCE2FC" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </TreeView.ItemContainerStyle>

    <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type viewmodels:ObjectBaseViewModel}" ItemsSource="{Binding Children}">
            <Border Name="ItemBorder" CornerRadius="2" Background="{Binding Background, RelativeSource={RelativeSource AncestorType=TreeViewItem}}"
                      BorderBrush="{Binding BorderBrush, RelativeSource={RelativeSource AncestorType=TreeViewItem}}" BorderThickness="1">
                <StackPanel Orientation="Horizontal" Margin="2">
                    <Image Name="icon" Source="/ExplorerTreeView/Images/folder.png"/>
                    <TextBlock Text="{Binding Name}"/>
                </StackPanel>
            </Border>
        </HierarchicalDataTemplate>
    </TreeView.Resources>
</TreeView>

---

解决方案

有了 Sheridan 和 Meleak 的出色回答，我的 TreeView 现在在代码中看起来像这样（我对此结果非常满意，并且非常接近 Explorer 的风格）：

<TreeView 
...
    <TreeView.ItemContainerStyle>
        <Style TargetType="{x:Type TreeViewItem}">
            <!-- Style for the selected item -->
            <Setter Property="BorderThickness" Value="1"/>
            <Style.Triggers>
                <!-- Selected and has focus -->
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="BorderBrush" Value="#7DA2CE"/>
                </Trigger>
                <!-- Mouse over -->
                <Trigger Property="helpers:TreeView_IsMouseDirectlyOverItem.IsMouseDirectlyOverItem" Value="True">
                    <Setter Property="Background">
                        <Setter.Value>
                            <LinearGradientBrush EndPoint="0,1" StartPoint="0,0">
                                <GradientStop Color="#FFFAFBFD" Offset="0"/>
                                <GradientStop Color="#FFEBF3FD" Offset="1"/>
                            </LinearGradientBrush>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="BorderBrush" Value="#B8D6FB"/>
                </Trigger>
                <!-- Selected but does not have the focus -->
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsSelected" Value="True"/>
                        <Condition Property="IsSelectionActive" Value="False"/>
                    </MultiTrigger.Conditions>
                    <Setter Property="BorderBrush" Value="#D9D9D9"/>
                </MultiTrigger>
            </Style.Triggers>
            <Style.Resources>
                <Style TargetType="Border">
                    <Setter Property="CornerRadius" Value="2"/>
                </Style>
            </Style.Resources>
        </Style>
    </TreeView.ItemContainerStyle>

    <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type viewmodels:ObjectBaseViewModel}" ItemsSource="{Binding Children}">
            <StackPanel Orientation="Horizontal" Margin="2,1,5,2">
                <Grid Margin="0,0,3,0">
                    <Image Name="icon" Source="/ExplorerTreeView/Images/folder.png"/>
                </Grid>
                <TextBlock Text="{Binding Name}" />
            </StackPanel>
        </HierarchicalDataTemplate>

        <!-- Brushes for the selected item -->
        <LinearGradientBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFDCEBFC" Offset="0"/>
            <GradientStop Color="#FFC1DBFC" Offset="1"/>
        </LinearGradientBrush>
        <LinearGradientBrush x:Key="{x:Static SystemColors.ControlBrushKey}" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFF8F8F8" Offset="0"/>
            <GradientStop Color="#FFE5E5E5" Offset="1"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
    </TreeView.Resources>
</TreeView>

Answer 1

添加到@Sheridan 的答案
这不是 100% 准确，但应该可以让您非常接近（它使用来自 GridView 的颜色，这与 Windows 资源管理器非常接近）

<TreeView ...>
    <TreeView.Resources>
        <LinearGradientBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFD9F4FF" Offset="0"/>
            <GradientStop Color="#FF9BDDFB" Offset="1"/>
        </LinearGradientBrush>
        <LinearGradientBrush x:Key="{x:Static SystemColors.ControlBrushKey}" EndPoint="0,1" StartPoint="0,0">
            <GradientStop Color="#FFEEEDED" Offset="0"/>
            <GradientStop Color="#FFDDDDDD" Offset="1"/>
        </LinearGradientBrush>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
    </TreeView.Resources>
    <TreeView.ItemContainerStyle>
        <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="BorderThickness" Value="1.5"/>
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="BorderBrush" Value="#adc6e5"/>
                </Trigger>
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsSelected" Value="True"/>
                        <Condition Property="IsSelectionActive" Value="False"/>
                    </MultiTrigger.Conditions>
                    <Setter Property="BorderBrush" Value="LightGray"/>
                </MultiTrigger>
            </Style.Triggers>
            <Style.Resources>
                <Style TargetType="Border">
                    <Setter Property="CornerRadius" Value="2"/>
                </Style>
            </Style.Resources>                    
        </Style>
    </TreeView.ItemContainerStyle>
</TreeView>

Answer 2

将其添加到您的 TreeView.ContainerStyle 中以删除默认的蓝色 背景。

<Style.Resources>
    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
    <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Transparent" />
    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
    <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
</Style.Resources>

您可以将黑色替换为您想要的项目文本和所选项目文本的任何颜色。

要在未聚焦时具有灰色背景，您可以设置带有灰色背景的“非聚焦”Style，并在 TreeViewItem.GotFocus< 上使用 EventTrigger。 /code> 和 LostFocus 事件在 Style 之间切换。

编辑>>

如果您想要 Flash，您可以通过直接在 HierarchicalDataTemplate 中向 ItemBorder Border 添加触发器来使用动画在背景颜色之间进行更改，如下所示：

<Border.Triggers>
    <EventTrigger RoutedEvent="Border.GotFocus">
        <EventTrigger.Actions>
            <BeginStoryboard>
                <Storyboard>
                    <ColorAnimation Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" To="YourColour" Duration="0:0:0.2" />
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger.Actions>
    </EventTrigger>
    <EventTrigger RoutedEvent="Border.LostFocus">
        <EventTrigger.Actions>
            <BeginStoryboard>
                <Storyboard>
                    <ColorAnimation Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" To="LightGray" Duration="0:0:0.2" />
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger.Actions>
    </EventTrigger>
</Border.Triggers>

请注意，这只会如果 ColorAnimation 具有 From 颜色，则有效。按照此代码，运行时将查找在 Border.Background 属性上设置的 SolidColorBrush，因此您必须设置一个。您可以直接设置 ColorAnimation.From 属性。

Answer 3

Windows 10 TreeView （和 ListView） 样式

我最初是在寻找一种将 Windows 10 配色方案应用于 TreeViewItem 的方法，包括

• 当前项目上的 IsMouseOver 仅
• Windows 10 颜色，WPF 已将它们应用于 ListBox < em>（不是 Windows 资源管理器）

---

如果你们中有人正在寻找这个，请随意使用下面的代码。我使用 Helge Klein 的解决方案来解决 IsMouseOver 问题，并将 Windows 10 颜色应用到 XAML。因此，我建议将此作为已接受答案的补充。

另外，请参阅下面有关 ListView 和 ComboBox 的说明。

---

屏幕截图

App.xaml

<Style TargetType="{x:Type TreeView}">
    <Style.Resources>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="#CBE8F6" />
        <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="#F6F6F6" />
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
    </Style.Resources>
</Style>
<Style TargetType="{x:Type TreeViewItem}">
    <Setter Property="BorderThickness" Value="1" />
    <Style.Triggers>
        <Trigger Property="IsSelected" Value="True">
            <Setter Property="BorderBrush" Value="#26A0DA" />
        </Trigger>
        <MultiTrigger>
            <MultiTrigger.Conditions>
                <Condition Property="local:TreeViewItemHelper.IsMouseDirectlyOverItem" Value="True" />
                <Condition Property="IsSelected" Value="False" />
            </MultiTrigger.Conditions>
            <Setter Property="Background" Value="#E5F3FB" />
            <Setter Property="BorderBrush" Value="#70C0E7" />
        </MultiTrigger>
        <MultiTrigger>
            <MultiTrigger.Conditions>
                <Condition Property="IsSelected" Value="True" />
                <Condition Property="IsSelectionActive" Value="False" />
            </MultiTrigger.Conditions>
            <Setter Property="BorderBrush" Value="#DADADA" />
        </MultiTrigger>
    </Style.Triggers>
</Style>

TreeViewItemHelper（作者：Helge Klein，细微更改/简化）

public static class TreeViewItemHelper
{
    private static TreeViewItem CurrentItem;
    private static readonly RoutedEvent UpdateOverItemEvent = EventManager.RegisterRoutedEvent("UpdateOverItem", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(TreeViewItemHelper));
    private static readonly DependencyPropertyKey IsMouseDirectlyOverItemKey = DependencyProperty.RegisterAttachedReadOnly("IsMouseDirectlyOverItem", typeof(bool), typeof(TreeViewItemHelper), new FrameworkPropertyMetadata(null, new CoerceValueCallback(CalculateIsMouseDirectlyOverItem)));
    public static readonly DependencyProperty IsMouseDirectlyOverItemProperty = IsMouseDirectlyOverItemKey.DependencyProperty;

    static TreeViewItemHelper()
    {
        EventManager.RegisterClassHandler(typeof(TreeViewItem), UIElement.MouseEnterEvent, new MouseEventHandler(OnMouseTransition), true);
        EventManager.RegisterClassHandler(typeof(TreeViewItem), UIElement.MouseLeaveEvent, new MouseEventHandler(OnMouseTransition), true);
        EventManager.RegisterClassHandler(typeof(TreeViewItem), UpdateOverItemEvent, new RoutedEventHandler(OnUpdateOverItem));
    }
    public static bool GetIsMouseDirectlyOverItem(DependencyObject obj)
    {
        return (bool)obj.GetValue(IsMouseDirectlyOverItemProperty);
    }
    private static object CalculateIsMouseDirectlyOverItem(DependencyObject item, object value)
    {
        return item == CurrentItem;
    }
    private static void OnUpdateOverItem(object sender, RoutedEventArgs e)
    {
        CurrentItem = sender as TreeViewItem;
        CurrentItem.InvalidateProperty(IsMouseDirectlyOverItemProperty);
        e.Handled = true;
    }
    private static void OnMouseTransition(object sender, MouseEventArgs e)
    {
        lock (IsMouseDirectlyOverItemProperty)
        {
            if (CurrentItem != null)
            {
                DependencyObject oldItem = CurrentItem;
                CurrentItem = null;
                oldItem.InvalidateProperty(IsMouseDirectlyOverItemProperty);
            }

            Mouse.DirectlyOver?.RaiseEvent(new RoutedEventArgs(UpdateOverItemEvent));
        }
    }
}

ListBox/ListView 和 ComboBox：在 Windows 7（和 8？） 中，这将导致从 TreeView 到 ListBox/ListView 和 ComboBox 的设计有所不同。因此，如果您也想将此配色方案应用于这些控件类型，请使用：

<Style TargetType="{x:Type ListBoxItem}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListBoxItem}">
                <Border Name="Border" BorderThickness="1" Background="Transparent">
                    <ContentPresenter />
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="Border" Property="Background" Value="#E5F3FB" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="#70C0E7" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter TargetName="Border" Property="Background" Value="#CBE8F6" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="#26A0DA" />
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsSelected" Value="True" />
                            <Condition Property="Selector.IsSelectionActive" Value="False" />
                        </MultiTrigger.Conditions>
                        <Setter TargetName="Border" Property="Background" Value="#F6F6F6" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="#DADADA" />
                    </MultiTrigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
<Style TargetType="{x:Type ListViewItem}" BasedOn="{StaticResource {x:Type ListBoxItem}}" />
<Style TargetType="{x:Type ComboBoxItem}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                <Border Name="Border" BorderThickness="1" Padding="1" Background="Transparent">
                    <ContentPresenter />
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="Border" Property="Background" Value="#E5F3FB" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="#70C0E7" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter TargetName="Border" Property="Background" Value="#CBE8F6" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="#26A0DA" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>