TreeViewItem parent 节点 & child 节点悬停在 child 节点上时 IsSelected 分离

Question

我真的不知道怎么问这个问题，但我想在我的 TreeView 上实现一个特定的样式。

因此，据我了解 TreeView 控件，当您展开 TreeViewItem 节点以查看它的 children 时，它会创建一个新的 ItemsPresenter，它是新 child 节点的 TreeViewItem。这意味着所有 child 节点都连接到它们的每个 parent。

我想要实现的是，当 child 展开到视图中并选择 parent 节点时，用户将鼠标悬停在 child 节点之一上，即parent 节点仍然激活了默认选择的样式。而不是通过将鼠标悬停在其中一个 children 节点上来激活 IsMouseOver 样式。

举个例子：

已选择parent颜色

选择 parent 并将鼠标悬停在 child 节点上时发生了什么

当 parent 节点被选中并且悬停在其中一个 children 上时我希望它看起来像什么（请原谅我惊人的绘画技巧用这个）

这是我的编码供参考

树视图

    <TreeView Background="{x:Null}" BorderThickness="0" Margin="0,3,0,0">
        <TreeViewItem  Header="Root Node" IsExpanded="True">
            <TreeViewItem Header="Parent Node" IsExpanded="True">
                <TreeViewItem Header="Child Node" IsExpanded="True">
                    <TreeViewItem Header="Child Node" IsExpanded="True">
                        <TreeViewItem Header="Child Node" IsExpanded="True" IsSelected="True"/>
                    </TreeViewItem>
                </TreeViewItem>
            </TreeViewItem>
            ...
            <TreeViewItem Header="Child Node">
                <TreeViewItem Header="Child Node"/>
                <TreeViewItem Header="Child Node"/>
            </TreeViewItem>
            <TreeViewItem Header="Child Node"/>
        </TreeViewItem>
    </TreeView>

风格

<Style x:Key="{x:Type TreeViewItem}" TargetType="{x:Type TreeViewItem}">
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
    <Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
    <Setter Property="Padding" Value="1,0,0,0"/>
    <Setter Property="Foreground" Value="Black"/>
    <Setter Property="FocusVisualStyle" Value="{StaticResource TreeViewItemFocusVisual}"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TreeViewItem}">
                <StackPanel>
                    <Border x:Name="Bd" Grid.ColumnSpan="3" BorderThickness="1" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true" Margin="3,0,3,-1" MinHeight="20">
                        <Border.Style>
                            <Style TargetType="{x:Type Border}">
                                <Style.Triggers>
                                    <Trigger Property="IsMouseOver" Value="true">
                                        <Setter Property="Background" Value="Red"/>
                                        <Setter Property="BorderBrush" Value="Black"/>
                                    </Trigger>
                                    <Trigger Property="IsMouseOver" Value="false">
                                        <Setter Property="Background" Value="Transparent"/>
                                    </Trigger>
                                </Style.Triggers>
                            </Style>
                        </Border.Style>
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition MinWidth="19" Width="Auto"/>
                                <ColumnDefinition Width="Auto"/>
                            </Grid.ColumnDefinitions>
                            <ToggleButton x:Name="Expander" ClickMode="Press" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ExpandCollapseToggleStyle}"/>
                            <ContentPresenter x:Name="PART_Header" ContentSource="Header" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                        </Grid>
                    </Border>

                    <ItemsPresenter x:Name="ItemsHost" Grid.ColumnSpan="2" Grid.Column="1" Grid.Row="1"/>
                </StackPanel>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsExpanded" Value="false">
                        <Setter Property="Visibility" TargetName="ItemsHost" Value="Collapsed"/>
                    </Trigger>
                    <Trigger Property="HasItems" Value="false">
                        <Setter Property="Visibility" TargetName="Expander" Value="Hidden"/>
                    </Trigger>
                    <Trigger Property="IsSelected" Value="true">
                        <Setter Property="Background" TargetName="Bd" Value="Green"/>
                        <Setter Property="BorderBrush" TargetName="Bd" Value="Black"/>
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsSelected" Value="true"/>
                            <Condition Property="IsMouseOver" Value="true"/>
                        </MultiTrigger.Conditions>
                        <Setter Property="Background" TargetName="Bd" Value="Red"/>
                    </MultiTrigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

如果有人有任何提示可以帮助我实现这一目标，我将不胜感激。此外，如果我尝试在 XAML 而不是在 C# 中完成大部分工作，但如果无法完成，我很乐意在 C# 中完成。谢谢。

Answer 1

我刚刚在这里添加了一些代码。

<Style x:Key="{x:Type TreeViewItem}" TargetType="{x:Type TreeViewItem}">
                <Setter Property="Background" Value="Transparent"/>
                <Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
                <Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
                <Setter Property="Padding" Value="1,0,0,0"/>
                <Setter Property="Foreground" Value="Black"/>
                <Setter Property="FocusVisualStyle" Value="{StaticResource TreeViewItemFocusVisual}"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type TreeViewItem}">
                            <StackPanel>
                                <Border x:Name="Bd" Grid.ColumnSpan="3" BorderThickness="1" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true" Margin="3,0,3,-1" MinHeight="20">
                                    <Border.Style>
                                        <Style TargetType="{x:Type Border}">
                                            <Style.Triggers>
                                                <Trigger Property="IsMouseOver" Value="true">
                                                    <Setter Property="Background" Value="Red"/>
                                                    <Setter Property="BorderBrush" Value="Black"/>
                                                </Trigger>
                                                <Trigger Property="IsMouseOver" Value="false">
                                                    <Setter Property="Background" Value="Transparent"/>
                                                </Trigger>
                                            </Style.Triggers>
                                        </Style>
                                    </Border.Style>
                                    <Grid>
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition MinWidth="19" Width="Auto"/>
                                            <ColumnDefinition Width="Auto"/>
                                        </Grid.ColumnDefinitions>
                                        <ToggleButton x:Name="Expander" ClickMode="Press" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ExpandCollapseToggleStyle}"/>
                                        <ContentPresenter x:Name="PART_Header" ContentSource="Header" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                    </Grid>
                                </Border>

                                <ItemsPresenter x:Name="ItemsHost" Grid.ColumnSpan="2" Grid.Column="1" Grid.Row="1"/>
                            </StackPanel>
                            <ControlTemplate.Triggers>
                                <Trigger Property="IsExpanded" Value="false">
                                    <Setter Property="Visibility" TargetName="ItemsHost" Value="Collapsed"/>
                                </Trigger>
                                <Trigger Property="HasItems" Value="false">
                                    <Setter Property="Visibility" TargetName="Expander" Value="Hidden"/>
                                </Trigger>
                                <Trigger Property="IsSelected" Value="true">
                                    <Setter Property="Background" TargetName="Bd" Value="Green"/>
                                    <Setter Property="BorderBrush" TargetName="Bd" Value="Black"/>
                                </Trigger>
                                <MultiTrigger>
                                    <MultiTrigger.Conditions>
                                        <Condition Property="IsSelected" Value="true"/>
                                        <Condition Property="IsMouseOver" Value="true"/>
                                    </MultiTrigger.Conditions>
                                    <Setter Property="Background" TargetName="Bd" Value="Red"/>
                                </MultiTrigger>
                                <Trigger Property="IsEnabled" Value="false">
                                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                                </Trigger>


                                <!--begin: I added just this, but you can cleanup your xaml and made it better, this just showing how you can do-->
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsSelected}" Value="true"/>
                                        <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsMouseOver}" Value="true"/>
                                        <Condition Binding="{Binding ElementName=ItemsHost, Path=IsMouseOver}" Value="True"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="Bd" Value="Green"/>
                                </MultiDataTrigger>
                                <!--end-->

                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>

TreeViewItem parent 节点 & child 节点悬停在 child 节点上时 IsSelected 分离

TreeViewItem parent node & child node IsSelected separation when hovering over a child node

c#

wpf

treeview

xaml

treeviewitem