WPF TreeView : How to style selected items with rounded corners like in Explorer

Question

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

我想将背景更改为 Windows 7 资源管理器中的样子(带/不带焦点):

到目前为止，我所尝试的并没有删除原来的深蓝色背景，而是在其顶部绘制了圆形边框，以便您在边缘和左侧看到深蓝色 - 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 shown此处或here 。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>

<小时/>

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，但应该非常接近(它使用 GridView 中的颜色，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>