TreeView 样式和模板

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本主题介绍 TreeView 控件的样式和模板。 可以修改默认 ControlTemplate 以赋予控件独特的外观。 有关详细信息，请参阅为控件创建模板。

TreeView 部件

TreeView 控件没有任何命名部件。

为 TreeView 创建 ControlTemplate 时，模板的 ScrollViewer 中可能包含 ItemsPresenter。 （ItemsPresenter 显示 TreeView 中的每个项；ScrollViewer 支持在控件内滚动）。 如果 ItemsPresenter 不是 ScrollViewer 的直接子元素，则必须为 ItemsPresenter 指定名称 ItemsPresenter。

TreeView 状态

下表列出了 TreeView 控件的可视状态。

VisualState 名称 VisualStateGroup 名称 说明
有效 ValidationStates 该控件使用 Validation 类，Validation.HasError 附加属性为 false。
InvalidFocused ValidationStates 如果控件具有焦点，则 Validation.HasError 附加属性为 true。
InvalidUnfocused ValidationStates Validation.HasError 附加属性是让控件不具有焦点的 true。

TreeViewItem 部件

下表列出了 TreeViewItem 控件的已命名部件。

组成部分 类型 描述
PART_Header FrameworkElement 包含 TreeView 控件的标头内容的视觉元素。

TreeViewItem 状态

下表列出了 TreeViewItem 控件的视觉对象状态。

VisualState 名称 VisualStateGroup 名称 说明
普通 CommonStates 默认状态。
MouseOver CommonStates 鼠标指针悬停在 TreeViewItem 上方。
已禁用 CommonStates 禁用 TreeViewItem。
Focused FocusStates TreeViewItem 具有焦点。
失去焦点 FocusStates TreeViewItem 没有焦点。
展开 ExpansionStates TreeViewItem 控件已展开。
Collapsed ExpansionStates TreeViewItem 控件已折叠。
HasItems HasItemsStates TreeViewItem 具有项。
NoItems HasItemsStates TreeViewItem 没有项。
已选择 SelectionStates TreeViewItem 处于选中状态。
SelectedInactive SelectionStates TreeViewItem 处于选中状态，但未处于活动状态。
未选定 SelectionStates TreeViewItem 处于未选中状态。
有效 ValidationStates 该控件使用 Validation 类，Validation.HasError 附加属性为 false。
InvalidFocused ValidationStates 如果控件具有焦点，则 Validation.HasError 附加属性为 true。
InvalidUnfocused ValidationStates Validation.HasError 附加属性是让控件不具有焦点的 true。

TreeView ControlTemplate 示例

以下示例演示如何定义 TreeView 控件的 ControlTemplate 及其关联类型。

<Style x:Key="{x:Type TreeView}"
       TargetType="TreeView">
  <Setter Property="OverridesDefaultStyle"
          Value="True" />
  <Setter Property="SnapsToDevicePixels"
          Value="True" />
  <Setter Property="ScrollViewer.HorizontalScrollBarVisibility"
          Value="Auto" />
  <Setter Property="ScrollViewer.VerticalScrollBarVisibility"
          Value="Auto" />
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="TreeView">
        <Border Name="Border"
                CornerRadius="1"
                BorderThickness="1">
          <Border.BorderBrush>
            <SolidColorBrush Color="{DynamicResource BorderMediumColor}" />
          </Border.BorderBrush>
          <Border.Background>
            <SolidColorBrush Color="{DynamicResource ControlLightColor}" />
          </Border.Background>
          <ScrollViewer Focusable="False"
                        CanContentScroll="False"
                        Padding="4">
            <ItemsPresenter />
          </ScrollViewer>
        </Border>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

<Style x:Key="ExpandCollapseToggleStyle"
       TargetType="ToggleButton">
  <Setter Property="Focusable"
          Value="False" />
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="ToggleButton">
        <Grid Width="15"
              Height="13"
              Background="Transparent">
          <VisualStateManager.VisualStateGroups>
            <VisualStateGroup x:Name="CheckStates">
              <VisualState x:Name="Checked">
                <Storyboard>
                  <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
                                                 Storyboard.TargetName="Collapsed">
                    <DiscreteObjectKeyFrame KeyTime="0"
                                            Value="{x:Static Visibility.Hidden}" />
                  </ObjectAnimationUsingKeyFrames>
                  <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
                                                 Storyboard.TargetName="Expanded">
                    <DiscreteObjectKeyFrame KeyTime="0"
                                            Value="{x:Static Visibility.Visible}" />
                  </ObjectAnimationUsingKeyFrames>
                </Storyboard>
              </VisualState>
              <VisualState x:Name="Unchecked" />
              <VisualState x:Name="Indeterminate" />
            </VisualStateGroup>
          </VisualStateManager.VisualStateGroups>
          <Path x:Name="Collapsed"
                HorizontalAlignment="Left"
                VerticalAlignment="Center"
                Margin="1,1,1,1"
                Data="M 4 0 L 8 4 L 4 8 Z">
            <Path.Fill>
              <SolidColorBrush Color="{DynamicResource GlyphColor}" />
            </Path.Fill>
          </Path>
          <Path x:Name="Expanded"
                HorizontalAlignment="Left"
                VerticalAlignment="Center"
                Margin="1,1,1,1"
                Data="M 0 4 L 8 4 L 4 8 Z"
                Visibility="Hidden">
            <Path.Fill>
              <SolidColorBrush Color="{DynamicResource GlyphColor}" />
            </Path.Fill>
          </Path>
        </Grid>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>
<Style x:Key="TreeViewItemFocusVisual">
  <Setter Property="Control.Template">
    <Setter.Value>
      <ControlTemplate>
        <Border>
          <Rectangle Margin="0,0,0,0"
                     StrokeThickness="5"
                     Stroke="Black"
                     StrokeDashArray="1 2"
                     Opacity="0" />
        </Border>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>
<Style x:Key="{x:Type TreeViewItem}"
       TargetType="{x:Type TreeViewItem}">
  <Setter Property="Background"
          Value="Transparent" />
  <Setter Property="HorizontalContentAlignment"
          Value="{Binding Path=HorizontalContentAlignment,
    RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" />
  <Setter Property="VerticalContentAlignment"
          Value="{Binding Path=VerticalContentAlignment,
    RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" />
  <Setter Property="Padding"
          Value="1,0,0,0" />
  <Setter Property="Foreground"
          Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" />
  <Setter Property="FocusVisualStyle"
          Value="{StaticResource TreeViewItemFocusVisual}" />
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type TreeViewItem}">
        <Grid>
          <Grid.ColumnDefinitions>
            <ColumnDefinition MinWidth="19"
                              Width="Auto" />
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
          </Grid.ColumnDefinitions>
          <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition />
          </Grid.RowDefinitions>
          <VisualStateManager.VisualStateGroups>
            <VisualStateGroup x:Name="SelectionStates">
              <VisualState x:Name="Selected">
                <Storyboard>
                  <ColorAnimationUsingKeyFrames Storyboard.TargetName="Bd"
                                                Storyboard.TargetProperty="(Panel.Background).
                    (SolidColorBrush.Color)"
                                                >
                    <EasingColorKeyFrame KeyTime="0"
                                         Value="{StaticResource SelectedBackgroundColor}" />
                  </ColorAnimationUsingKeyFrames>
                </Storyboard>
              </VisualState>
              <VisualState x:Name="Unselected" />
              <VisualState x:Name="SelectedInactive">
                <Storyboard>
                  <ColorAnimationUsingKeyFrames Storyboard.TargetName="Bd"
                                                Storyboard.TargetProperty="(Panel.Background).
                    (SolidColorBrush.Color)">
                    <EasingColorKeyFrame KeyTime="0"
                                         Value="{StaticResource SelectedUnfocusedColor}" />
                  </ColorAnimationUsingKeyFrames>
                </Storyboard>
              </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="ExpansionStates">
              <VisualState x:Name="Expanded">
                <Storyboard>
                  <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
                                                 Storyboard.TargetName="ItemsHost">
                    <DiscreteObjectKeyFrame KeyTime="0"
                                            Value="{x:Static Visibility.Visible}" />
                  </ObjectAnimationUsingKeyFrames>
                </Storyboard>
              </VisualState>
              <VisualState x:Name="Collapsed" />
            </VisualStateGroup>
          </VisualStateManager.VisualStateGroups>
          <ToggleButton x:Name="Expander"
                        Style="{StaticResource ExpandCollapseToggleStyle}"
                        ClickMode="Press"
                        IsChecked="{Binding IsExpanded, 
            RelativeSource={RelativeSource TemplatedParent}}"/>
          <Border x:Name="Bd"
                  Grid.Column="1"
                  Background="{TemplateBinding Background}"
                  BorderBrush="{TemplateBinding BorderBrush}"
                  BorderThickness="{TemplateBinding BorderThickness}"
                  Padding="{TemplateBinding Padding}">
            <ContentPresenter x:Name="PART_Header"
                              ContentSource="Header"
                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"/>
          </Border>
          <ItemsPresenter x:Name="ItemsHost"
                          Grid.Row="1"
                          Grid.Column="1"
                          Grid.ColumnSpan="2"
                          Visibility="Collapsed" />
        </Grid>
        <ControlTemplate.Triggers>
          <Trigger Property="HasItems"
                   Value="false">
            <Setter TargetName="Expander"
                    Property="Visibility"
                    Value="Hidden" />
          </Trigger>
          <MultiTrigger>
            <MultiTrigger.Conditions>
              <Condition Property="HasHeader"
                         Value="false" />
              <Condition Property="Width"
                         Value="Auto" />
            </MultiTrigger.Conditions>
            <Setter TargetName="PART_Header"
                    Property="MinWidth"
                    Value="75" />
          </MultiTrigger>
          <MultiTrigger>
            <MultiTrigger.Conditions>
              <Condition Property="HasHeader"
                         Value="false" />
              <Condition Property="Height"
                         Value="Auto" />
            </MultiTrigger.Conditions>
            <Setter TargetName="PART_Header"
                    Property="MinHeight"
                    Value="19" />
          </MultiTrigger>
        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

上一示例使用了一个或多个以下资源。

<!--Control colors.-->
<Color x:Key="WindowColor">#FFE8EDF9</Color>
<Color x:Key="ContentAreaColorLight">#FFC5CBF9</Color>
<Color x:Key="ContentAreaColorDark">#FF7381F9</Color>

<Color x:Key="DisabledControlLightColor">#FFE8EDF9</Color>
<Color x:Key="DisabledControlDarkColor">#FFC5CBF9</Color>
<Color x:Key="DisabledForegroundColor">#FF888888</Color>

<Color x:Key="SelectedBackgroundColor">#FFC5CBF9</Color>
<Color x:Key="SelectedUnfocusedColor">#FFDDDDDD</Color>

<Color x:Key="ControlLightColor">White</Color>
<Color x:Key="ControlMediumColor">#FF7381F9</Color>
<Color x:Key="ControlDarkColor">#FF211AA9</Color>

<Color x:Key="ControlMouseOverColor">#FF3843C4</Color>
<Color x:Key="ControlPressedColor">#FF211AA9</Color>


<Color x:Key="GlyphColor">#FF444444</Color>
<Color x:Key="GlyphMouseOver">sc#1, 0.004391443, 0.002428215, 0.242281124</Color>

<!--Border colors-->
<Color x:Key="BorderLightColor">#FFCCCCCC</Color>
<Color x:Key="BorderMediumColor">#FF888888</Color>
<Color x:Key="BorderDarkColor">#FF444444</Color>

<Color x:Key="PressedBorderLightColor">#FF888888</Color>
<Color x:Key="PressedBorderDarkColor">#FF444444</Color>

<Color x:Key="DisabledBorderLightColor">#FFAAAAAA</Color>
<Color x:Key="DisabledBorderDarkColor">#FF888888</Color>

<Color x:Key="DefaultBorderBrushDarkColor">Black</Color>

<!--Control-specific resources.-->
<Color x:Key="HeaderTopColor">#FFC5CBF9</Color>
<Color x:Key="DatagridCurrentCellBorderColor">Black</Color>
<Color x:Key="SliderTrackDarkColor">#FFC5CBF9</Color>

<Color x:Key="NavButtonFrameColor">#FF3843C4</Color>

<LinearGradientBrush x:Key="MenuPopupBrush"
                     EndPoint="0.5,1"
                     StartPoint="0.5,0">
  <GradientStop Color="{DynamicResource ControlLightColor}"
                Offset="0" />
  <GradientStop Color="{DynamicResource ControlMediumColor}"
                Offset="0.5" />
  <GradientStop Color="{DynamicResource ControlLightColor}"
                Offset="1" />
</LinearGradientBrush>

<LinearGradientBrush x:Key="ProgressBarIndicatorAnimatedFill"
                     StartPoint="0,0"
                     EndPoint="1,0">
  <LinearGradientBrush.GradientStops>
    <GradientStopCollection>
      <GradientStop Color="#000000FF"
                    Offset="0" />
      <GradientStop Color="#600000FF"
                    Offset="0.4" />
      <GradientStop Color="#600000FF"
                    Offset="0.6" />
      <GradientStop Color="#000000FF"
                    Offset="1" />
    </GradientStopCollection>
  </LinearGradientBrush.GradientStops>
</LinearGradientBrush>

有关完整示例，请参阅使用 ControlTemplates 设置样式示例。

另请参阅