ShrlAlgoToolkit/Melskin/Controls/Cascader.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:assists="clr-namespace:Melskin.Assists"
    xmlns:controls="clr-namespace:Melskin.Controls"
    xmlns:converters="clr-namespace:Melskin.Converters"
    xmlns:internal="clr-namespace:Melskin.Converters.Internal">

    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="/Melskin;component/Themes/Animations.xaml" />
    </ResourceDictionary.MergedDictionaries>


    <Style x:Key="DefaultCascaderPanelStyle" TargetType="ListBox">
        <!--<Setter Property="ItemContainerStyle" Value="{DynamicResource DefaultCascaderListBoxItemStyle}" />-->
        <Setter Property="Background" Value="{DynamicResource BackgroundFloatingBrush}" />
        <Setter Property="BorderBrush" Value="{DynamicResource BorderNormalBrush}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="Foreground" Value="{DynamicResource TextPrimaryBrush}" />
        <Setter Property="FontSize" Value="14" />
        <Setter Property="Padding" Value="10,4" />
        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
        <!-- <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" /> -->
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
        <Setter Property="ScrollViewer.CanContentScroll" Value="true" />
        <Setter Property="ScrollViewer.PanningMode" Value="Both" />
        <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="AlternationCount" Value="{Binding RelativeSource={RelativeSource Self}, Path=Items.Count}" />
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" />
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <DataTemplate>
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="Auto" />
                        </Grid.ColumnDefinitions>

                        <!--  核心修正：使用 TextBlock 并通过 MultiBinding 设置 Text  -->
                        <TextBlock Grid.Column="0" VerticalAlignment="Center">
                            <TextBlock.Text>
                                <MultiBinding Converter="{x:Static internal:PropertyValueConverter.Instance}">
                                    <!--  第一个绑定：当前的数据项  -->
                                    <Binding Path="." />
                                    <!--  第二个绑定：从祖先 Cascader 获取 DisplayMemberPath  -->
                                    <Binding Path="DisplayMemberPath" RelativeSource="{RelativeSource AncestorType=controls:Cascader}" />
                                </MultiBinding>
                            </TextBlock.Text>
                        </TextBlock>
                        <controls:IconElement
                            x:Name="Arrow"
                            Grid.Column="1"
                            Width="8"
                            Height="8"
                            Foreground="{DynamicResource TextPrimaryBrush}"
                            Symbol="KeyboardArrowRight"
                            Visibility="Hidden" />
                    </Grid>
                    <DataTemplate.Triggers>
                        <DataTrigger Value="True">
                            <DataTrigger.Binding>
                                <MultiBinding Converter="{x:Static internal:HasChildrenMultiConverter.Instance}">
                                    <Binding Path="." />
                                    <Binding Path="SubmenuMemberPath" RelativeSource="{RelativeSource AncestorType=controls:Cascader}" />
                                </MultiBinding>
                            </DataTrigger.Binding>
                            <Setter TargetName="Arrow" Property="Visibility" Value="Visible" />
                        </DataTrigger>
                    </DataTemplate.Triggers>
                </DataTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListBox}">
                    <Border
                        x:Name="Bd"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="4"
                        SnapsToDevicePixels="true">
                        <ScrollViewer Focusable="false">
                            <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
                        </ScrollViewer>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter TargetName="Bd" Property="Background" Value="{DynamicResource ControlBackgroundDisabledBrush}" />
                        </Trigger>
                        <MultiTrigger>
                            <MultiTrigger.Conditions>
                                <Condition Property="IsGrouping" Value="true" />
                                <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false" />
                            </MultiTrigger.Conditions>
                            <Setter Property="ScrollViewer.CanContentScroll" Value="false" />
                        </MultiTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <Style TargetType="{x:Type controls:Cascader}">
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="Background" Value="{DynamicResource ControlBackgroundNormalBrush}" />
        <Setter Property="BorderBrush" Value="Transparent" />
        <Setter Property="Foreground" Value="{DynamicResource TextPrimaryBrush}" />
        <Setter Property="Padding" Value="10,6" />
        <Setter Property="FontSize" Value="14" />
        <Setter Property="VerticalAlignment" Value="Center" />
        <Setter Property="assists:InputAssist.Clearable" Value="True" />
        <Setter Property="assists:InputAssist.PlaceholderText" Value="请选择..." />
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
        <Setter Property="ScrollViewer.CanContentScroll" Value="True" />
        <Setter Property="ScrollViewer.PanningMode" Value="Both" />
        <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
        <Setter Property="PanelStyle" Value="{StaticResource DefaultCascaderPanelStyle}" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type controls:Cascader}">
                    <Grid x:Name="templateRoot" SnapsToDevicePixels="true">
                        <ToggleButton
                            x:Name="PART_ToggleButton"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            IsChecked="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}"
                            Style="{DynamicResource ComboBoxToggleButton}" />
                        <TextBlock
                            Margin="{TemplateBinding Padding}"
                            VerticalAlignment="Center"
                            IsHitTestVisible="False"
                            Text="{Binding SelectedText, RelativeSource={RelativeSource AncestorType=controls:Cascader}}"
                            TextTrimming="CharacterEllipsis" />
                        <TextBlock
                            x:Name="Placeholder"
                            Margin="{TemplateBinding Padding}"
                            Padding="3"
                            VerticalAlignment="Center"
                            Foreground="{DynamicResource TextPlaceholderBrush}"
                            IsHitTestVisible="False"
                            Text="{Binding Path=(assists:InputAssist.PlaceholderText), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=controls:Cascader}}">
                            <TextBlock.Style>
                                <Style TargetType="TextBlock">
                                    <Setter Property="Visibility" Value="Collapsed" />
                                    <Style.Triggers>
                                        <DataTrigger Binding="{Binding SelectedText, RelativeSource={RelativeSource AncestorType=controls:Cascader}}" Value="">
                                            <Setter Property="Visibility" Value="Visible" />
                                        </DataTrigger>
                                    </Style.Triggers>
                                </Style>
                            </TextBlock.Style>
                        </TextBlock>
                        <Popup
                            x:Name="PART_Popup"
                            Margin="-8"
                            assists:BehaviorAssist.SimulateNativeBehavior="True"
                            AllowsTransparency="True"
                            IsOpen="{Binding IsChecked, ElementName=PART_ToggleButton}"
                            Placement="Bottom"
                            PlacementTarget="{Binding ElementName=PART_ToggleButton}"
                            PopupAnimation="Slide"
                            StaysOpen="True">
                            <Border
                                x:Name="PART_Border"
                                MinWidth="{Binding ActualWidth, ElementName=templateRoot}"
                                MaxHeight="300"
                                Margin="8"
                                Background="{DynamicResource BackgroundFloatingBrush}"
                                BorderBrush="{DynamicResource BorderNormalBrush}"
                                BorderThickness="1"
                                CornerRadius="4"
                                Effect="{DynamicResource PopupShadow}"
                                SnapsToDevicePixels="True">
                                <Grid>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="Auto" />
                                        <RowDefinition Height="*" />
                                    </Grid.RowDefinitions>
                                    <TextBox
                                        x:Name="PART_SearchBox"
                                        Grid.Row="0"
                                        Margin="4"
                                        Text="{Binding SearchText, RelativeSource={RelativeSource TemplatedParent}, UpdateSourceTrigger=PropertyChanged}">
                                        <assists:InputAssist.Suffix>
                                            <controls:IconElement
                                                Width="16"
                                                Height="16"
                                                Margin="4,2,2,0"
                                                Foreground="{DynamicResource TextSecondaryBrush}"
                                                Symbol="Search" />
                                        </assists:InputAssist.Suffix>
                                    </TextBox>
                                    <Grid Grid.Row="1">
                                        <ScrollViewer
                                            x:Name="PART_CascadingView"
                                            HorizontalScrollBarVisibility="Auto"
                                            VerticalScrollBarVisibility="Disabled">
                                            <ContentPresenter Content="{TemplateBinding CascadingPanel}" />
                                        </ScrollViewer>

                                        <!--  改造搜索结果列表  -->
                                        <ListBox
                                            x:Name="PART_SearchResultsView"
                                            HorizontalContentAlignment="Stretch"
                                            ItemsSource="{Binding FilteredItemsSource, RelativeSource={RelativeSource TemplatedParent}}"
                                            ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                                            Visibility="Collapsed">
                                            <ListBox.ItemTemplate>
                                                <DataTemplate>
                                                    <!--  使用一个完全透明的按钮来承载内容和命令  -->
                                                    <Button
                                                        Padding="4,2"
                                                        HorizontalContentAlignment="Stretch"
                                                        Command="{Binding RelativeSource={RelativeSource AncestorType=controls:Cascader}, Path=SelectSearchResultCommand}"
                                                        CommandParameter="{Binding}">
                                                        <Button.Template>
                                                            <ControlTemplate TargetType="Button">
                                                                <Border
                                                                    x:Name="Bd"
                                                                    Padding="{TemplateBinding Padding}"
                                                                    Background="Transparent">
                                                                    <ContentPresenter HorizontalAlignment="Left" VerticalAlignment="Center" />
                                                                </Border>
                                                                <ControlTemplate.Triggers>
                                                                    <Trigger Property="IsMouseOver" Value="True">
                                                                        <Setter TargetName="Bd" Property="Background" Value="{DynamicResource ControlBackgroundHoverBrush}" />
                                                                    </Trigger>
                                                                </ControlTemplate.Triggers>
                                                            </ControlTemplate>
                                                        </Button.Template>
                                                        <!--  按钮的内容就是之前定义的文本  -->
                                                        <TextBlock
                                                            Text="{Binding DisplayText}"
                                                            TextTrimming="CharacterEllipsis"
                                                            ToolTip="{Binding DisplayText}" />
                                                    </Button>
                                                </DataTemplate>
                                            </ListBox.ItemTemplate>
                                        </ListBox>
                                    </Grid>
                                </Grid>

                            </Border>
                        </Popup>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Background" Value="{DynamicResource ControlBackgroundHoverBrush}" />
                        </Trigger>
                        <Trigger Property="IsFocused" Value="True">
                            <Setter Property="BorderBrush" Value="{DynamicResource PrimaryFocusedBrush}" />
                        </Trigger>

                        <Trigger Property="IsEnabled" Value="False">
                            <Setter Property="Background" Value="{DynamicResource ControlBackgroundDisabledBrush}" />
                            <Setter Property="Foreground" Value="{DynamicResource TextDisabledBrush}" />
                        </Trigger>
                        <Trigger Property="IsDropDownOpen" Value="True">
                            <Setter Property="BorderBrush" Value="{DynamicResource PrimaryNormalBrush}" />
                        </Trigger>
                        <MultiDataTrigger>
                            <MultiDataTrigger.Conditions>
                                <Condition Binding="{Binding Path=SearchText, RelativeSource={RelativeSource Self}, Converter={x:Static converters:NullOrEmptyConverter.NotInstance}}" Value="True" />
                            </MultiDataTrigger.Conditions>
                            <Setter TargetName="PART_CascadingView" Property="Visibility" Value="Collapsed" />
                            <Setter TargetName="PART_SearchResultsView" Property="Visibility" Value="Visible" />
                        </MultiDataTrigger>
                        <Trigger Property="IsSearchable" Value="False">
                            <Setter TargetName="PART_SearchBox" Property="Visibility" Value="Collapsed" />
                            <Setter TargetName="PART_Border" Property="Background" Value="Transparent" />
                            <Setter TargetName="PART_Border" Property="BorderThickness" Value="0" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>