Treeview hide [+] [-] buttons

Question

Does anyone know how to hide the [-] button for a treeview? The treeview will never be collapsed, and therefore I dont need the root node to have the collapse option. I know I could use a listview with a stye that indents the [0] element to act like a treeview root node. However the binding I'm using etc. kind of asks for a treeview, and I'm not sure how to access the button and disable it.

Answer 1

This should work. You need to modify the ControlTemplate of the TreeViewItem, the [+] / [-] button is actually a ToggleButton inside the TreeViewItem's ControlTemplate so all you need to do is set its visibility to hidden or collapsed.

Create a project called "StackOverflowTests" (so you don't have to change anything) and paste this code in your Window1.xaml file. Should work right out of the box:

    <ControlTemplate x:Key="invisibleButtonTreeViewItemTemplate" TargetType="TreeViewItem" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto" MinWidth="19" />
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition />
            </Grid.RowDefinitions>
            <!-- Make the ToggleButton invisible -->
            <ToggleButton IsChecked="False" Visibility="Hidden" ClickMode="Press" Name="Expander" />
            <Border BorderThickness="{TemplateBinding Border.BorderThickness}" Padding="{TemplateBinding Control.Padding}" BorderBrush="{TemplateBinding Border.BorderBrush}" Background="{TemplateBinding Panel.Background}" Name="Bd" SnapsToDevicePixels="True" Grid.Column="1">
                <ContentPresenter Content="{TemplateBinding HeaderedContentControl.Header}" ContentTemplate="{TemplateBinding HeaderedContentControl.HeaderTemplate}" ContentStringFormat="{TemplateBinding HeaderedItemsControl.HeaderStringFormat}" ContentSource="Header" Name="PART_Header" HorizontalAlignment="{TemplateBinding Control.HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" />
            </Border>
            <ItemsPresenter Name="ItemsHost" Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="2" />
        </Grid>
        <ControlTemplate.Triggers>
            <!-- Remove this trigger so it does not collapse on double click or-->
            <!--<Trigger Property="TreeViewItem.IsExpanded">
                <Setter Property="UIElement.Visibility" TargetName="ItemsHost">
                    <Setter.Value>
                        <x:Static Member="Visibility.Collapsed" />
                    </Setter.Value>
                </Setter>
                <Trigger.Value>
                    <s:Boolean>False</s:Boolean>
                </Trigger.Value>
            </Trigger>-->
            <Trigger Property="ItemsControl.HasItems">
                <Setter Property="UIElement.Visibility" TargetName="Expander">
                    <Setter.Value>
                        <x:Static Member="Visibility.Hidden" />
                    </Setter.Value>
                </Setter>
                <Trigger.Value>
                    <s:Boolean>False</s:Boolean>
                </Trigger.Value>
            </Trigger>
            <Trigger Property="TreeViewItem.IsSelected">
                <Setter Property="Panel.Background" TargetName="Bd">
                    <Setter.Value>
                        <DynamicResource ResourceKey="{x:Static SystemColors.HighlightBrushKey}" />
                    </Setter.Value>
                </Setter>
                <Setter Property="TextElement.Foreground">
                    <Setter.Value>
                        <DynamicResource ResourceKey="{x:Static SystemColors.HighlightTextBrushKey}" />
                    </Setter.Value>
                </Setter>
                <Trigger.Value>
                    <s:Boolean>True</s:Boolean>
                </Trigger.Value>
            </Trigger>
            <MultiTrigger>
                <MultiTrigger.Conditions>
                    <Condition Property="TreeViewItem.IsSelected">
                        <Condition.Value>
                            <s:Boolean>True</s:Boolean>
                        </Condition.Value>
                    </Condition>
                    <Condition Property="Selector.IsSelectionActive">
                        <Condition.Value>
                            <s:Boolean>False</s:Boolean>
                        </Condition.Value>
                    </Condition>
                </MultiTrigger.Conditions>
                <Setter Property="Panel.Background" TargetName="Bd">
                    <Setter.Value>
                        <DynamicResource ResourceKey="{x:Static SystemColors.ControlBrushKey}" />
                    </Setter.Value>
                </Setter>
                <Setter Property="TextElement.Foreground">
                    <Setter.Value>
                        <DynamicResource ResourceKey="{x:Static SystemColors.ControlTextBrushKey}" />
                    </Setter.Value>
                </Setter>
            </MultiTrigger>
            <Trigger Property="UIElement.IsEnabled">
                <Setter Property="TextElement.Foreground">
                    <Setter.Value>
                        <DynamicResource ResourceKey="{x:Static SystemColors.GrayTextBrushKey}" />
                    </Setter.Value>
                </Setter>
                <Trigger.Value>
                    <s:Boolean>False</s:Boolean>
                </Trigger.Value>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <Style TargetType="{x:Type TreeViewItem}">

        <Setter Property="Template" Value="{StaticResource invisibleButtonTreeViewItemTemplate}" />
    </Style>

</Window.Resources>
<TreeView>
    <TreeViewItem Header="Item 1" IsExpanded="True">
        <TreeViewItem Header="Item 1.1" IsExpanded="True" />
        <TreeViewItem Header="Item 1.2" IsExpanded="True">
            <TreeViewItem Header="Item 1.2.1" IsExpanded="True" />
        </TreeViewItem>
    </TreeViewItem>
    <TreeViewItem Header="Item 2" IsExpanded="True">
        <TreeViewItem Header="Item 2.1" IsExpanded="True" />
    </TreeViewItem>
</TreeView>

Answer 2

I implemented this recently. On the TreeView control I just set:

IsHitTestVisible="False"

and added into my app.xaml:

<Style TargetType="TreeViewItem">
    <Setter Property="IsExpanded" Value="True" />
</Style>

Though this removes the ability to select any of the TreeViewItems. I just did it because I wanted the simple hierachical representation of some data I had.