Tuy*_*ham 36
让我回答我自己的问题.

码
您需要做的就是XAML文件和后面的代码:
首先你需要绘制切换按钮:从三角形按钮到加号 - 减号按钮:绘制一个带有深色边框的矩形,然后绘制两条线,一条垂直线和一条水平线.展开TreeViewItem时,垂直线将隐藏:
<!-- Toggle Button -->
<Style x:Key="ExpandCollapseToggleStyle" TargetType="ToggleButton">
<Setter Property="Focusable" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ToggleButton">
<Grid Width="15" Height="13" SnapsToDevicePixels="True">
<!-- Rectangle 9x9 pixels -->
<Rectangle Width="9" Height="9" Stroke="#919191" SnapsToDevicePixels="true">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.5,2" StartPoint="0.5,0">
<GradientStop Color="White" Offset="0"/>
<GradientStop Color="Silver" Offset="0.5"/>
<GradientStop Color="LightGray" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
</Rectangle>
<!-- Vertical line inside rectangle -->
<Rectangle x:Name="ExpandPath" Width="1" Height="5" Stroke="Black" SnapsToDevicePixels="true"/>
<!-- Horizontal line inside rectangle -->
<Rectangle Width="5" Height="1" Stroke="Black" SnapsToDevicePixels="true"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Visibility" TargetName="ExpandPath" Value="Collapsed"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
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在上面的代码中,您可以看到一个触发器,如果项目展开,它将使内部垂直线切换按钮隐藏,或者显示其子项是否折叠.
然后,您需要在节点之间绘制垂直和水平连接线:您需要重新设计TreeViewItem Control.添加这些连接线:
<!-- Horizontal line -->
<Rectangle x:Name="HorLn" Margin="9,1,0,0" Height="1" Stroke="#DCDCDC" SnapsToDevicePixels="True"/>
<!-- Vertical line -->
<Rectangle x:Name="VerLn" Width="1" Stroke="#DCDCDC" Margin="0,0,1,0" Grid.RowSpan="2" SnapsToDevicePixels="true" Fill="White"/>
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到您的TreeViewItem模板,如下所示:
<!-- TreeViewItem -->
<Style x:Key="{x:Type TreeViewItem}" TargetType="{x:Type TreeViewItem}">
<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>
<!-- Connecting Lines -->
<!-- Horizontal line -->
<Rectangle x:Name="HorLn" Margin="9,1,0,0" Height="1" Stroke="#DCDCDC" SnapsToDevicePixels="True"/>
<!-- Vertical line -->
<Rectangle x:Name="VerLn" Width="1" Stroke="#DCDCDC" Margin="0,0,1,0" Grid.RowSpan="2" SnapsToDevicePixels="true" Fill="White"/>
<!-- Insert Toggle Button -->
<ToggleButton Margin="-1,0,0,0" 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}" MinWidth="20"/>
</Border>
<ItemsPresenter x:Name="ItemsHost" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
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然后,您需要将类TreeViewLineConverter放入您的命名空间.如果项目是列表中的最后一项,则此类将更改连接线:
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
namespace TreeViewEx
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
}
class TreeViewLineConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
TreeViewItem item = (TreeViewItem)value;
ItemsControl ic = ItemsControl.ItemsControlFromItemContainer(item);
return ic.ItemContainerGenerator.IndexFromContainer(item) == ic.Items.Count - 1;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return false;
}
}
}
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将命名空间插入XAML,即:
<Window x:Class="TreeViewEx.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:TreeViewEx"/>
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将此行添加到Window.Resources:
<local:TreeViewLineConverter x:Key="LineConverter"/>
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向TreeViewItem模板添加触发器,如果该项是列表中的最后一个,则此触发器会更改连接线:
<!-- This trigger changes the connecting lines if the item is the last in the list -->
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Converter={StaticResource LineConverter}}" Value="true">
<Setter TargetName="VerLn" Property="Height" Value="9"/>
<Setter TargetName="VerLn" Property="VerticalAlignment" Value="Top"/>
</DataTrigger>
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TreeView现在将具有WinForms风格.如果需要,可以添加更多触发器来控制TreeView的行为.完整触发器可以在附件上找到.
去做
在WinForms TreeView中,连接线是虚线.要使这些线条点缀,请更改:
<!-- Connecting Lines -->
<Rectangle x:Name="HorLn" Margin="9,1,0,0" Height="1" Stroke="#DCDCDC" SnapsToDevicePixels="True"/>
<Rectangle x:Name="VerLn" Width="1" Stroke="#DCDCDC" Margin="0,0,1,0" Grid.RowSpan="2" SnapsToDevicePixels="true" Fill="White"/>
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至:
<!-- Connecting Lines -->
<Rectangle x:Name="HorLn" Margin="9,1,0,0" Height="1" Stroke="Blue" StrokeDashCap="Square" StrokeDashArray="0,2" StrokeDashOffset="1" SnapsToDevicePixels="True"/>
<Rectangle x:Name="VerLn" Width="1" Stroke="Blue" StrokeDashCap="Square" StrokeDashArray="0,2" Margin="0,0,1,0" Grid.RowSpan="2" SnapsToDevicePixels="true" Fill="White"/>
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但是你看,它并不漂亮.由于我是WPF的新手,我不知道如何完美地设计这些线条.
问题!
将TreeViewItem添加到TreeView时,垂直线有问题:

您可能会建议我更改垂直线大小,但如果您更改字体大小,它也将无效.
源代码
你可以在这里下载我的源代码:
https://tuyentk.googlecode.com/files/TreeViewEx.zip(4.4 KB)
参考
这是我在编写自己的代码之前所引用的代码:Social MSDN:显示用虚线连接的TreeView节点
很好的例子。虚线解决方案中的问题是您使用矩形作为宽度或高度设置为 1 的线。如果这样做,则左右边框位于同一像素上。如果这些线是实线,那就没问题,但如果它们是点线,则不必在相同位置有点(即左边框从像素 0 处的点开始,右边框从像素 1 处开始),这种行为会使您的线条不漂亮。
解决方案是使用与矩形不同的东西创建虚线。例如,您可以使用Border. 我从这里采取了解决方案。
将连接线更改为:
<!-- Connecting Lines -->
<Border x:Name="HorLn" Margin="9,0,0,0" HorizontalAlignment="Stretch" Height="1" BorderThickness="0,0,0,1">
<Border.BorderBrush>
<LinearGradientBrush StartPoint="0,0" EndPoint="2,0" SpreadMethod="Repeat" MappingMode="Absolute">
<GradientStop Color="Transparent" Offset="0" />
<GradientStop Color="Transparent" Offset="0.499" />
<GradientStop Color="#999" Offset="0.5" />
</LinearGradientBrush>
</Border.BorderBrush>
</Border>
<Border x:Name="VerLn" Margin="0,0,1,0" Grid.RowSpan="2" VerticalAlignment="Stretch" Width="1" BorderThickness="0,0,1,0">
<Border.BorderBrush>
<LinearGradientBrush StartPoint="0,0" EndPoint="0,2" SpreadMethod="Repeat" MappingMode="Absolute">
<GradientStop Color="Transparent" Offset="0" />
<GradientStop Color="Transparent" Offset="0.499" />
<GradientStop Color="#999" Offset="0.5" />
</LinearGradientBrush>
</Border.BorderBrush>
</Border>
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