WPF：如何防止滚动条在列表类型视图中覆盖 headers

Question

我制作了一个 ScrollViewer 样式，旨在显示覆盖可滚动内容的滚动条。我根据其他 Whosebug 帖子 such as this.

制作了它

许多其他场景与我的场景之间的区别在于，我将滚动查看器样式应用于包含 header 的 ListView。通常，用户希望滚动查看器不会像我下面的图片那样覆盖 headers。（我用橙色突出显示了该栏以使其更加明显）

（该条应该在 header 开始之前停止。重要的是要提到可滚动内容的第一个元素没有隐藏在 header 下面。在我的图像中将栏向下滚动 ~15%。）

我尝试将滚动查看器中的滚动条固定在底部并将它们的高度设置为 "ViewportHeight"，还尝试将各种元素放置在网格的第二行（第 1 行）中（参见下面的代码）无济于事。

如何让滚动查看器在 header 的底部之前停止？

<Style x:Key="StandardScrollViewer" TargetType="{x:Type ScrollViewer}">
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="BorderBrush" Value="{DynamicResource BackgroundGreyLevel2}" />
        <Setter Property="Background" Value="{DynamicResource CollectionControlBackgroundGradient}" />
        <Setter Property="VerticalScrollBarVisibility" Value="Hidden"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="Auto" />
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>
                        <DockPanel Margin="{TemplateBinding Padding}" Grid.ColumnSpan="2" Grid.RowSpan="1">
                            <ScrollViewer DockPanel.Dock="Top" Grid.ColumnSpan="2" Grid.RowSpan="2" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden" Focusable="False">
                                <GridViewHeaderRowPresenter x:Name="GridViewHeaderRowPresenter" Margin="2,0,2,0"   Columns="{Binding Path=TemplatedParent.View.Columns, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderContainerStyle="{Binding Path=TemplatedParent.View.ColumnHeaderContainerStyle, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderTemplate="{Binding Path=TemplatedParent.View.ColumnHeaderTemplate, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderTemplateSelector="{Binding Path=TemplatedParent.View.ColumnHeaderTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}" AllowsColumnReorder="{Binding Path=TemplatedParent.View.AllowsColumnReorder, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderContextMenu="{Binding Path=TemplatedParent.View.ColumnHeaderContextMenu, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderToolTip="{Binding Path=TemplatedParent.View.ColumnHeaderToolTip, RelativeSource={RelativeSource TemplatedParent}}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                            </ScrollViewer>
                            <ScrollContentPresenter Name="PART_ScrollContentPresenter" KeyboardNavigation.DirectionalNavigation="Local" CanContentScroll="{TemplateBinding CanContentScroll}" Grid.ColumnSpan="2" Grid.RowSpan="2"/>
                        </DockPanel>
                        <ScrollBar Name="PART_VerticalScrollBar"
                                   HorizontalAlignment="Right" 
                                   Grid.Column="1"
                                   Grid.Row="0"
                                   VerticalAlignment="Stretch"
                                   Value="{TemplateBinding VerticalOffset}"
                                   Maximum="{TemplateBinding ScrollableHeight}"
                                   ViewportSize="{TemplateBinding ViewportHeight}"
                                   Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" />
                        <ScrollBar Name="PART_HorizontalScrollBar"
                                   VerticalAlignment="Bottom"
                                   Orientation="Horizontal"
                                   Grid.Row="1"
                                   Value="{TemplateBinding HorizontalOffset}"
                                   Maximum="{TemplateBinding ScrollableWidth}"
                                   ViewportSize="{TemplateBinding ViewportWidth}"
                                   Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>

Answer 1

这比我想象的更容易修复，部分原因是（与我的信念相反）WPF 对于呈现滚动内容的元素的源 WPF ordering/positioning 并不重要和滚动条（停靠面板和上面两个滚动条中的所有内容）。

因此，只需在视图中添加一个额外的（第 3 行）行，我可以在其中放置我的 headers。然后我简单地将内容和垂直滚动条的指定行更改为 +1 之前的内容。

结果是滚动条包含在与滚动内容相同的行中，因此不会泄漏到 headers 上。

<ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="Auto" />
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto" />
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>
                        <GridViewHeaderRowPresenter x:Name="GridViewHeaderRowPresenter" Margin="2,0,2,0" Grid.Row="0" Columns="{Binding Path=TemplatedParent.View.Columns, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderContainerStyle="{Binding Path=TemplatedParent.View.ColumnHeaderContainerStyle, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderTemplate="{Binding Path=TemplatedParent.View.ColumnHeaderTemplate, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderTemplateSelector="{Binding Path=TemplatedParent.View.ColumnHeaderTemplateSelector, RelativeSource={RelativeSource TemplatedParent}}" AllowsColumnReorder="{Binding Path=TemplatedParent.View.AllowsColumnReorder, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderContextMenu="{Binding Path=TemplatedParent.View.ColumnHeaderContextMenu, RelativeSource={RelativeSource TemplatedParent}}" ColumnHeaderToolTip="{Binding Path=TemplatedParent.View.ColumnHeaderToolTip, RelativeSource={RelativeSource TemplatedParent}}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                        <DockPanel Margin="{TemplateBinding Padding}" Grid.Row="1" Grid.ColumnSpan="2" Grid.RowSpan="1">
                            <ScrollViewer DockPanel.Dock="Top" Grid.Row="1" Grid.ColumnSpan="2" Grid.RowSpan="2" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden" Focusable="False">
                            </ScrollViewer>
                            <ScrollContentPresenter Name="PART_ScrollContentPresenter" KeyboardNavigation.DirectionalNavigation="Local" CanContentScroll="{TemplateBinding CanContentScroll}" Grid.ColumnSpan="2" Grid.RowSpan="2"/>
                        </DockPanel>
                        <ScrollBar Name="PART_VerticalScrollBar"
                                   HorizontalAlignment="Right" 
                                   Grid.Column="1"
                                   Grid.Row="1"
                                   VerticalAlignment="Stretch"
                                   Value="{TemplateBinding VerticalOffset}"
                                   Maximum="{TemplateBinding ScrollableHeight}"
                                   ViewportSize="{TemplateBinding ViewportHeight}"
                                   Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" />
                        <ScrollBar Name="PART_HorizontalScrollBar"
                                   VerticalAlignment="Bottom"
                                   Orientation="Horizontal"
                                   Grid.Row="1"
                                   Value="{TemplateBinding HorizontalOffset}"
                                   Maximum="{TemplateBinding ScrollableWidth}"
                                   ViewportSize="{TemplateBinding ViewportWidth}"
                                   Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"/>
                    </Grid>
                </ControlTemplate>

以上是我修改的唯一一段代码。

此外，作为参考，this article 非常有帮助。

WPF：如何防止滚动条在列表类型视图中覆盖 headers

WPF: How to prevent scrollbar from overlaying headers in list type views

c#

wpf

user-interface

scrollbar

scrollviewer