我正在合并两个在互联网上找到的示例。一个是关于拉伸选择样式,另一个是关于树形多选。
除了树形视图的缩进之外,我已经让所有代码正常运行。我可以提供所有代码,但那样解决不了问题。
我的问题出现在以下方法中:
public static class TreeViewItemExtensions
{
public static int GetDepth(this TreeViewItem item)
{
FrameworkElement elem = item;
while (elem.Parent != null)
{
var tvi = elem.Parent as TreeViewItem;
if (tvi != null)
return tvi.GetDepth() + 1;
elem = elem.Parent as FrameworkElement;
}
return 0;
}
}
该方法试图检索树中TreeViewItem的深度。问题在于:
elem.Parent
始终为null,这导致深度为0。
我认为这是因为我正在使用HierarchicalDataTemplate
。我的xaml的一部分如下所示。
<TreeView Name="folderTree"
ItemsSource="{Binding Folders}"
SelectedItemChanged="folderTree_SelectedItemChanged"
HorizontalContentAlignment="Stretch">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Folders}"
DataType="{x:Type Model:IFolder}">
<StackPanel Orientation="Horizontal">
<StackPanel.Style>
<Style TargetType="{x:Type StackPanel}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsSelected}"
Value="True">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<Image Source="{Binding Converter={StaticResource iconConverter}}" Height="{Binding ElementName=theFile,Path=ActualHeight}"/>
<TextBlock Text="{Binding FileName}" Name="theFile"/>
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
我的树形视图样式的XAML如下:
<Style x:Key="{x:Type TreeViewItem}" TargetType="{x:Type TreeViewItem}">
<!-- leaving some stuff out here -->
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TreeViewItem}">
<ControlTemplate.Resources>
<local:LeftMarginMultiplierConverter Length="19" x:Key="lengthConverter" />
</ControlTemplate.Resources>
<StackPanel>
<!-- The upper part of the TreeViewItem -->
<Border Name="Bd"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}">
<!-- The margin is what we try to measure, how can we get the parents from the templatedParents? -->
<Grid Margin="{Binding Converter={StaticResource lengthConverter},
RelativeSource={RelativeSource TemplatedParent},
Path=.}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="19" />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<ToggleButton x:Name="Expander"
Style="{StaticResource ExpandCollapseToggleStyle}"
IsChecked="{Binding Path=IsExpanded,
RelativeSource={RelativeSource TemplatedParent}}"
ClickMode="Press"/>
<ContentPresenter x:Name="PART_Header"
Grid.Column="1"
ContentSource="Header"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"/>
</Grid>
</Border>
<!-- the children of the TreeViewItem -->
<ItemsPresenter x:Name="ItemsHost" />
</StackPanel>
<!-- leaving some stuff out here with triggers -->
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
如何让HierarchicalDataTemplate填充Parent属性?
TreeViewItem
添加到树中时,为什么会有父子关系呢? - Marnix