有没有一种“最佳实践”的方法来替换默认模板的部分内容?当前使用情况是树状视图。在默认情况下,树状视图有小三角形图案用于展开和折叠。
我知道如果替换整个控件模板就可以替换这些内容,如下面的代码所示。不确定是否有一种方法“保留所有默认,只更改XY”。这不是一个样式,我基本上需要替换现有控件模板的一部分。
为了说明,看一下下面的XAML。第一个较小的块是我想要适应的相关XAML。
更大的第二部分和第三部分基本上是默认模板的副本,只是为了管理从一开始就“更改”了的部分。
是否有更好的方法来完成这个任务,避免使用第二部分中这么长而且容易混淆的XAML代码?
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<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">
<Path x:Name="ExpandPath"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Margin="1,1,1,1"
Fill="Black"
Data="M 4 0 L 8 4 L 4 8 Z"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked"
Value="True">
<Setter Property="Data"
TargetName="ExpandPath"
Value="M 0 4 L 8 4 L 4 8 Z"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<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}">
<ContentPresenter x:Name="PART_Header"
ContentSource="Header"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"/>
</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>
<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>
<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>