当Background（或应用程序）失去焦点时，如何更改所选TreeViewItem的{{1}}。默认情况下，所选项目在此情况下为浅灰色背景。
编辑：第一次回答后尝试：但是找不到包含TreeView的元素。
TargetName="Bd"答案 0 :(得分：4)
您需要修改TreeViewItem的默认样式。特别是，您需要修改以下触发器：
<Style x:Key="{x:Type TreeViewItem}"
TargetType="{x:Type TreeViewItem}">
...
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TreeViewItem}">
...
<ControlTemplate.Triggers>
...
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected"
Value="true"/>
<Condition Property="IsSelectionActive"
Value="false"/>
</MultiTrigger.Conditions>
<Setter TargetName="Bd"
Property="Background"
Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
</MultiTrigger>
...
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
...
</Style>
正如您所看到的，如果项目被聚焦且选择未激活（焦点位于其他位置），触发器会将背景设置为{DynamicResource {x:Static SystemColors.ControlBrushKey}}。
<强>更新
Aero主题的完整风格TreeViewItem如下所示：
<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>
<ToggleButton x:Name="Expander"
Style="{StaticResource ExpandCollapseToggleStyle}"
IsChecked="{Binding Path=IsExpanded,RelativeSource={RelativeSource TemplatedParent}}"
ClickMode="Press"/>
<Border Name="Bd"
Grid.Column="1"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}"
SnapsToDevicePixels="true">
<ContentPresenter x:Name="PART_Header"
ContentSource="Header"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
<ItemsPresenter x:Name="ItemsHost"
Grid.Row="1"
Grid.Column="1"
Grid.ColumnSpan="2"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded"
Value="false">
<Setter TargetName="ItemsHost"
Property="Visibility"
Value="Collapsed"/>
</Trigger>
<Trigger Property="HasItems"
Value="false">
<Setter TargetName="Expander"
Property="Visibility"
Value="Hidden"/>
</Trigger>
<Trigger Property="IsSelected"
Value="true">
<Setter TargetName="Bd"
Property="Background"
Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected"
Value="true"/>
<Condition Property="IsSelectionActive"
Value="false"/>
</MultiTrigger.Conditions>
<Setter TargetName="Bd"
Property="Background"
Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
</MultiTrigger>
<Trigger Property="IsEnabled"
Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="VirtualizingStackPanel.IsVirtualizing"
Value="true">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
为此您还需要这个：
<PathGeometry x:Key="TreeArrow">
<PathGeometry.Figures>
<PathFigureCollection>
<PathFigure IsFilled="True"
StartPoint="0 0"
IsClosed="True">
<PathFigure.Segments>
<PathSegmentCollection>
<LineSegment Point="0 6"/>
<LineSegment Point="6 0"/>
</PathSegmentCollection>
</PathFigure.Segments>
</PathFigure>
</PathFigureCollection>
</PathGeometry.Figures>
</PathGeometry>
<Style x:Key="ExpandCollapseToggleStyle"
TargetType="{x:Type ToggleButton}">
<Setter Property="Focusable"
Value="False"/>
<Setter Property="Width"
Value="16"/>
<Setter Property="Height"
Value="16"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Width="16"
Height="16"
Background="Transparent"
Padding="5,5,5,5">
<Path x:Name="ExpandPath"
Fill="Transparent"
Stroke="#FF989898"
Data="{StaticResource TreeArrow}">
<Path.RenderTransform>
<RotateTransform Angle="135"
CenterX="3"
CenterY="3"/>
</Path.RenderTransform>
</Path>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver"
Value="True">
<Setter TargetName="ExpandPath"
Property="Stroke"
Value="#FF1BBBFA"/>
<Setter TargetName="ExpandPath"
Property="Fill"
Value="Transparent"/>
</Trigger>
<Trigger Property="IsChecked"
Value="True">
<Setter TargetName="ExpandPath"
Property="RenderTransform">
<Setter.Value>
<RotateTransform Angle="180"
CenterX="3"
CenterY="3"/>
</Setter.Value>
</Setter>
<Setter TargetName="ExpandPath"
Property="Fill"
Value="#FF595959"/>
<Setter TargetName="ExpandPath"
Property="Stroke"
Value="#FF262626"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
在所有这些中，您只需要修改您感兴趣的部分（如果选择处于非活动状态，则为背景颜色），并将这些样式放在主窗口的App.xaml的资源部分中。
答案 1 :(得分：3)
存在您的特定情况的更简单方法。与ListBox类似，您可以使用样式替换TreeViewItem的ControlBrush资源：
<Style TargetType="TreeViewItem">
<Style.Resources>
<SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="{x:Static SystemColors.HighlightColor}" Opacity=".4" />
</Style.Resources>
</Style>
您可以指定任何其他颜色。建议使用不透明度，因为如果您有多个TreeView / ListBox，则可以确定哪一个是聚焦的。但是，编辑完整样式当然可以为将来的自定义提供更大的灵活性。
渐变样本：
<Style TargetType="TreeViewItem">
<Style.Resources>
<LinearGradientBrush x:Key="{x:Static SystemColors.ControlBrushKey}" EndPoint='0 1'>
<GradientStop Color='#AA00FF00' />
<GradientStop Offset='1' Color='#AA007700' />
</LinearGradientBrush>
<LinearGradientBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" EndPoint='0 1'>
<GradientStop Color='#AA00FF00' />
<GradientStop Offset='1' Color='#AA007700' />
</LinearGradientBrush>
</Style.Resources>
</Style>
答案 2 :(得分：1)
如果您不想覆盖默认的控制模板，可以使用文本块为标题定义自己的模板，并将该模板中的样式应用于文本块本身（其中包含一个小填充） TreeViewItem的默认控件模板，因此您还应将其设置为零以实现像素完美。）
var iHeight = $(this).outerHeight() + 5;
element += iHeight;
$(this).css({
top: element,
position: 'absolute'
});