WPF ControlTemplate用于滚动TreeView控件

时间:2008-10-28 21:26:38

标签: c# wpf

我正在使用TreeView控件,当单击其中一个时,它会自动滚动到左对齐TreeViewItem。我已经去看了我的Styles和ControlTemplates,但我还没有找到任何东西。是否存在导致此问题的默认ControlTemplate?我想禁用它。

5 个答案:

答案 0 :(得分:7)

项目滚动,因为ScrollViewer在它们上调用BringIntoView()。因此,避免滚动的一种方法是禁止处理RequestBringIntoView事件。您可以通过继承TreeView并实例化此控件来快速尝试:

public class NoScrollTreeView : TreeView
{
    public class NoScrollTreeViewItem : TreeViewItem
    {
        public NoScrollTreeViewItem() : base()
        {
            this.RequestBringIntoView += delegate (object sender, RequestBringIntoViewEventArgs e) {
                e.Handled = true;
            };
        }

        protected override DependencyObject GetContainerForItemOverride()
        {
            return new NoScrollTreeViewItem();
        }
    }
    protected override DependencyObject GetContainerForItemOverride()
    {
        return new NoScrollTreeViewItem();
    }
}

答案 1 :(得分:6)

在这个问题上花了几个小时后,我发现了一个适合我的解决方案。

brians解决方案是防止TreeViewItem上的RequestBringIntoView事件冒泡的第一步。不幸的是,如果您通过

以编程方式更改所选项目,也会停止显示树视图项目
yourtreeview.SelectedItem = yourtreeviewitem

所以,对我来说,解决方法是修改treeview的controltemplate,如下所示:

<Style x:Key="{x:Type TreeView}" TargetType="TreeView">
        <Setter Property="OverridesDefaultStyle" Value="True" />
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="TreeView">
                    <Border Name="Border" BorderThickness="0" Padding="0" Margin="1">
                        <ScrollViewer Focusable="False" CanContentScroll="False" Padding="0">
                            <Components:AutoScrollPreventer Margin="0">
                                <ItemsPresenter/>
                            </Components:AutoScrollPreventer>
                        </ScrollViewer>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

“autoscrollpreventer”是:

using System;
using System.Windows;
using System.Windows.Controls;

namespace LiveContext.Designer.GUI.Components {
    public class AutoScrollPreventer : StackPanel
    {
    public AutoScrollPreventer() {

        this.RequestBringIntoView += delegate(object sender, RequestBringIntoViewEventArgs e)
        {
            // stop this event from bubbling so that a scrollviewer doesn't try to BringIntoView..
            e.Handled = true;
        };

    }
}

}

希望它有所帮助..

答案 2 :(得分:0)

看起来我在MSDN找到了一个很好的线索:

  

听起来这是一种互动   使用scrollviewer和焦点   系统

     

当元素聚焦在一个元素中时   ScrollViewer(是其中的一部分)   TreeView模板),ScrollViewer   被指示制作元素   可见。它会自动响应   滚动到请求的元素。

     

ScrollViewer中的方法   处理这些焦点请求的是   所有私人和/或内部所以你   真的无法得到他们。我不   认为你可以做的太多了   这个案例;这就是焦点的工作原理。

所以,是吗?当然有一种方法可以修改TreeView模板,以便ScrollViewer不会出现这种行为......

答案 3 :(得分:0)

好的,我终于能够得到这样的默认样式:

        using (Stream sw = File.Open(@"C:\TreeViewDefaults.xaml", FileMode.Truncate, FileAccess.Write))
        {
            Style ts = Application.Current.FindResource(typeof(TreeView)) as Style;
            if (ts != null)
                XamlWriter.Save(ts, sw);
        }

哪个产生了:

<Style TargetType="TreeView" 
       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">
    <Style.Triggers>
        <Trigger Property="VirtualizingStackPanel.IsVirtualizing">
            <Setter Property="ItemsControl.ItemsPanel">
                <Setter.Value>
                    <ItemsPanelTemplate><VirtualizingStackPanel IsItemsHost="True" /></ItemsPanelTemplate>
                </Setter.Value>
            </Setter>
            <Trigger.Value>
                <s:Boolean>True</s:Boolean>
            </Trigger.Value>
        </Trigger>
    </Style.Triggers>
    <Style.Resources>
        <ResourceDictionary />
    </Style.Resources>
    <Setter Property="Panel.Background">
        <Setter.Value><DynamicResource ResourceKey="{x:Static SystemColors.WindowBrushKey}" /></Setter.Value>
    </Setter>
    <Setter Property="Border.BorderBrush">
        <Setter.Value><SolidColorBrush>#FF828790</SolidColorBrush></Setter.Value>
    </Setter>
    <Setter Property="Border.BorderThickness">
        <Setter.Value><Thickness>1,1,1,1</Thickness></Setter.Value>
    </Setter>
    <Setter Property="Control.Padding">
        <Setter.Value><Thickness>1,1,1,1</Thickness></Setter.Value>
    </Setter>
    <Setter Property="TextElement.Foreground">
        <Setter.Value><DynamicResource ResourceKey="{x:Static SystemColors.ControlTextBrushKey}" /></Setter.Value>
    </Setter>
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility">
        <Setter.Value><x:Static Member="ScrollBarVisibility.Auto" /></Setter.Value>
    </Setter>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility">
        <Setter.Value><x:Static Member="ScrollBarVisibility.Auto" /></Setter.Value>
    </Setter>
    <Setter Property="Control.VerticalContentAlignment">
        <Setter.Value><x:Static Member="VerticalAlignment.Center" /></Setter.Value>
    </Setter>
    <Setter Property="Control.Template">
        <Setter.Value>
            <ControlTemplate TargetType="TreeView">
                <Border BorderThickness="{TemplateBinding Border.BorderThickness}" 
                        BorderBrush="{TemplateBinding Border.BorderBrush}" 
                        Name="Bd" SnapsToDevicePixels="True">
                    <ScrollViewer CanContentScroll="False" 
                                  HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" 
                                  VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" 
                                  Background="{TemplateBinding Panel.Background}" 
                                  Padding="{TemplateBinding Control.Padding}" 
                                  Name="_tv_scrollviewer_" 
                                  SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" 
                                  Focusable="False">
                        <ItemsPresenter />
                    </ScrollViewer>
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="UIElement.IsEnabled">
                        <Setter Property="Panel.Background" TargetName="Bd">
                            <Setter.Value>
                                <DynamicResource ResourceKey="{x:Static SystemColors.ControlBrushKey}" />
                            </Setter.Value>
                        </Setter>
                        <Trigger.Value>
                            <s:Boolean>False</s:Boolean>
                        </Trigger.Value>
                    </Trigger>
                    <Trigger Property="VirtualizingStackPanel.IsVirtualizing">
                        <Setter Property="ScrollViewer.CanContentScroll" TargetName="_tv_scrollviewer_">
                            <Setter.Value><s:Boolean>True</s:Boolean></Setter.Value>
                        </Setter>
                        <Trigger.Value>
                            <s:Boolean>True</s:Boolean>
                        </Trigger.Value>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

遗憾的是,这看起来并不有用。我没有看到任何属性来停止自动滚动焦点的事情。

仍在寻找...

答案 4 :(得分:0)

另一个有趣的花絮:有一个名为HandlesScrolling的可覆盖布尔值,它总是返回true。反编译源后,看起来这个属性永远不会被使用(或者它被用在XAML中的一些深,暗,秘密的地方)。我尝试使用自己的TreeView控件将此值设置为false,但它不起作用。