How to always show scrollbar?

问题

How to always show the scrollbar in a UWP app?

The scrollbar always disappears after a few seconds.

I have tried setting ScrollViewer.VerticalScrollBarVisibility="Visible", but the scrollbar still disappears.

I have had a look at the Xaml UI Basics sample, and the scroll bars also disappear here regardless of what properties I set.

This answer for Windows Phone 8 suggests modifying the scroll viewer template, but that seems like overkill.

Any ideas?

回答1:

For UWP use this style

<!-- In default here i enabled horizontal scrollbar visibility and mode you can disable it if you want -->

<Style x:Key="MyScrollViewerStyle" TargetType="ScrollViewer">
    <Setter Property="HorizontalScrollMode" Value="Enabled"/>
    <Setter Property="VerticalScrollMode" Value="Enabled"/>
    <Setter Property="IsHorizontalRailEnabled" Value="True"/>
    <Setter Property="IsVerticalRailEnabled" Value="True"/>
    <Setter Property="IsTabStop" Value="False"/>
    <Setter Property="ZoomMode" Value="Disabled"/>
    <Setter Property="HorizontalContentAlignment" Value="Left"/>
    <Setter Property="VerticalContentAlignment" Value="Top"/>
    <Setter Property="VerticalScrollBarVisibility" Value="Visible"/>
    <Setter Property="HorizontalScrollBarVisibility" Value="Visible"/>
    <Setter Property="Padding" Value="0"/>
    <Setter Property="BorderThickness" Value="0"/>
    <Setter Property="BorderBrush" Value="Transparent"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ScrollViewer">
                <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="ScrollingIndicatorStates">
                            <VisualState x:Name="TouchIndicator">
                                <Storyboard>
                                    <FadeOutThemeAnimation TargetName="ScrollBarSeparator"/>
                                    <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="IndicatorMode" Storyboard.TargetName="VerticalScrollBar">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <ScrollingIndicatorMode>TouchIndicator</ScrollingIndicatorMode>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="IndicatorMode" Storyboard.TargetName="HorizontalScrollBar">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <ScrollingIndicatorMode>TouchIndicator</ScrollingIndicatorMode>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="MouseIndicator">
                                <Storyboard>
                                    <FadeInThemeAnimation TargetName="ScrollBarSeparator"/>
                                    <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="IndicatorMode" Storyboard.TargetName="VerticalScrollBar">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <ScrollingIndicatorMode>MouseIndicator</ScrollingIndicatorMode>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="IndicatorMode" Storyboard.TargetName="HorizontalScrollBar">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <ScrollingIndicatorMode>MouseIndicator</ScrollingIndicatorMode>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Grid Background="{TemplateBinding Background}">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>
                        <ScrollContentPresenter x:Name="ScrollContentPresenter" Grid.ColumnSpan="2" ContentTemplate="{TemplateBinding ContentTemplate}" Margin="{TemplateBinding Padding}" Grid.RowSpan="2"/>
                        <ScrollBar x:Name="VerticalScrollBar" Grid.Column="1" HorizontalAlignment="Right" IsTabStop="False" Maximum="{TemplateBinding ScrollableHeight}" Orientation="Vertical" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{TemplateBinding VerticalOffset}" ViewportSize="{TemplateBinding ViewportHeight}"/>
                        <ScrollBar x:Name="HorizontalScrollBar" IsTabStop="False" Maximum="{TemplateBinding ScrollableWidth}" Orientation="Horizontal" Grid.Row="1" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{TemplateBinding HorizontalOffset}" ViewportSize="{TemplateBinding ViewportWidth}"/>
                        <Border x:Name="ScrollBarSeparator" Background="{ThemeResource SystemControlPageBackgroundChromeLowBrush}" Grid.Column="1" Grid.Row="1"/>
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Then reference it in your scrollviewer

<ScrollViewer Style="{StaticResource MyScrollViewerStyle}" Height="680" Width="480" HorizontalAlignment="Center" VerticalAlignment="Center">

    <Image Source="/Assets/wallpaper.jpg"/> <!-- or your items -->

</ScrollViewer>

来源：https://stackoverflow.com/questions/47583575/how-to-always-show-scrollbar