XAML 应用自适应触发器后出现渲染问题

Question

在我的 UWP 应用程序中，我有一个 Pivot 控件作为我的主要导航控件。通常 Pivot header 位于屏幕顶部。如果用户使用移动设备，我想要实现的是将 Pivot headers 移到底部。

我为每个州定义了 2 种样式。第一种样式是默认的 Pivot 样式。

第二种样式为底部状态（两者的区别已标出）：

      <Style x:Key="PivotStyleBottom" TargetType="Pivot">
        <Setter Property="Margin" Value="0"/>
        <Setter Property="Padding" Value="0"/>
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="IsTabStop" Value="False"/>
        <Setter Property="ItemsPanel">
            <Setter.Value>
                <ItemsPanelTemplate>
                    <Grid/>
                </ItemsPanelTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Pivot">
                    <Grid x:Name="RootElement" Background="{TemplateBinding Background}" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}">
                        <Grid.Resources>
                            <Style x:Key="BaseContentControlStyle" TargetType="ContentControl">
                                <Setter Property="FontFamily" Value="Segoe UI"/>
                                <Setter Property="FontWeight" Value="SemiBold"/>
                                <Setter Property="FontSize" Value="15"/>
                                <Setter Property="Template">
                                    <Setter.Value>
                                        <ControlTemplate TargetType="ContentControl">
                                            <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" OpticalMarginAlignment="TrimSideBearings" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                            <Style x:Key="TitleContentControlStyle" BasedOn="{StaticResource BaseContentControlStyle}" TargetType="ContentControl">
                                <Setter Property="FontFamily" Value="{ThemeResource PivotTitleFontFamily}"/>
                                <Setter Property="FontWeight" Value="{ThemeResource PivotTitleThemeFontWeight}"/>
                                <Setter Property="FontSize" Value="{ThemeResource PivotTitleFontSize}"/>
                            </Style>
                        </Grid.Resources>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto"/>
                            <RowDefinition Height="*"/>
                        </Grid.RowDefinitions>
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="Orientation">
                                <VisualState x:Name="Portrait">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="TitleContentControl">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource PivotPortraitThemePadding}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Landscape">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="TitleContentControl">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource PivotLandscapeThemePadding}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="NavigationButtonsVisibility">
                                <VisualState x:Name="NavigationButtonsHidden"/>
                                <VisualState x:Name="NavigationButtonsVisible">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="NextButton">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="1"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsEnabled" Storyboard.TargetName="NextButton">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="True"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PreviousButton">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="1"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsEnabled" Storyboard.TargetName="PreviousButton">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="True"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="HeaderStates">
                                <VisualState x:Name="HeaderDynamic"/>
                                <VisualState x:Name="HeaderStatic">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="Header">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="Collapsed"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="StaticHeader">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="Visible"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <ContentControl x:Name="TitleContentControl" ContentTemplate="{TemplateBinding TitleTemplate}" Content="{TemplateBinding Title}" IsTabStop="False" Margin="{StaticResource PivotPortraitThemePadding}" Style="{StaticResource TitleContentControlStyle}" Visibility="Collapsed"/>
                        <Grid Grid.Row="1">
                            <Grid.Resources>
                                <ControlTemplate x:Key="NextTemplate" TargetType="Button">
                                    <Border x:Name="Root" BorderBrush="{ThemeResource SystemControlForegroundTransparentBrush}" BorderThickness="{ThemeResource PivotNavButtonBorderThemeThickness}" Background="{ThemeResource SystemControlBackgroundBaseMediumLowBrush}">
                                        <VisualStateManager.VisualStateGroups>
                                            <VisualStateGroup x:Name="CommonStates">
                                                <VisualState x:Name="Normal"/>
                                                <VisualState x:Name="PointerOver">
                                                    <Storyboard>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Root">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="Arrow">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltAltMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                                <VisualState x:Name="Pressed">
                                                    <Storyboard>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Root">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="Arrow">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltAltMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                            </VisualStateGroup>
                                        </VisualStateManager.VisualStateGroups>
                                        <FontIcon x:Name="Arrow" Foreground="{ThemeResource SystemControlForegroundAltMediumHighBrush}" FontSize="12" FontFamily="{ThemeResource SymbolThemeFontFamily}" Glyph="&#xE0E3;" HorizontalAlignment="Center" MirroredWhenRightToLeft="True" UseLayoutRounding="False" VerticalAlignment="Center"/>
                                    </Border>
                                </ControlTemplate>
                                <ControlTemplate x:Key="PreviousTemplate" TargetType="Button">
                                    <Border x:Name="Root" BorderBrush="{ThemeResource SystemControlForegroundTransparentBrush}" BorderThickness="{ThemeResource PivotNavButtonBorderThemeThickness}" Background="{ThemeResource SystemControlBackgroundBaseMediumLowBrush}">
                                        <VisualStateManager.VisualStateGroups>
                                            <VisualStateGroup x:Name="CommonStates">
                                                <VisualState x:Name="Normal"/>
                                                <VisualState x:Name="PointerOver">
                                                    <Storyboard>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Root">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="Arrow">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltAltMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                                <VisualState x:Name="Pressed">
                                                    <Storyboard>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Root">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="Arrow">
                                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltAltMediumHighBrush}"/>
                                                        </ObjectAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                            </VisualStateGroup>
                                        </VisualStateManager.VisualStateGroups>
                                        <FontIcon x:Name="Arrow" Foreground="{ThemeResource SystemControlForegroundAltMediumHighBrush}" FontSize="12" FontFamily="{ThemeResource SymbolThemeFontFamily}" Glyph="&#xE0E2;" HorizontalAlignment="Center" MirroredWhenRightToLeft="True" UseLayoutRounding="False" VerticalAlignment="Center"/>
                                    </Border>
                                </ControlTemplate>
                            </Grid.Resources>
                            <ScrollViewer x:Name="ScrollViewer" BringIntoViewOnFocusChange="False" HorizontalSnapPointsAlignment="Center" HorizontalSnapPointsType="MandatorySingle" HorizontalScrollBarVisibility="Hidden" Margin="{TemplateBinding Padding}" Template="{StaticResource ScrollViewerScrollBarlessTemplate}" VerticalSnapPointsType="None" VerticalScrollBarVisibility="Disabled" VerticalScrollMode="Disabled" VerticalContentAlignment="Stretch" ZoomMode="Disabled">
                                <PivotPanel x:Name="Panel" VerticalAlignment="Stretch">
                                    <Grid x:Name="PivotLayoutElement">
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="Auto"/>
                                            <ColumnDefinition Width="*"/>
                                            <ColumnDefinition Width="Auto"/>
                                        </Grid.ColumnDefinitions>
                                        <Grid.RowDefinitions>
                                        <!--CHANGED-->
                                           <RowDefinition Height="*"/>
                                            <RowDefinition Height="Auto"/>
                                        </Grid.RowDefinitions>
                                        <Grid.RenderTransform>
                                            <CompositeTransform x:Name="PivotLayoutElementTranslateTransform"/>
                                        </Grid.RenderTransform>
                                          <!--CHANGED-->
                                        <ItemsPresenter x:Name="PivotItemPresenter" Grid.ColumnSpan="3" Grid.Row="0">
                                            <ItemsPresenter.RenderTransform>
                                                <TransformGroup>
                                                    <TranslateTransform x:Name="ItemsPresenterTranslateTransform"/>
                                                    <CompositeTransform x:Name="ItemsPresenterCompositeTransform"/>
                                                </TransformGroup>
                                            </ItemsPresenter.RenderTransform>
                                        </ItemsPresenter>
                                         <!--CHANGED-->
                                        <ContentPresenter Grid.Row="1" x:Name="LeftHeaderPresenter" ContentTemplate="{TemplateBinding LeftHeaderTemplate}" Content="{TemplateBinding LeftHeader}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
                                          <!--CHANGED-->
                                        <ContentControl Grid.Row="1" x:Name="HeaderClipper" Grid.Column="1" HorizontalContentAlignment="Stretch" UseSystemFocusVisuals="True">
                                            <ContentControl.Clip>
                                                <RectangleGeometry x:Name="HeaderClipperGeometry"/>
                                            </ContentControl.Clip>
                                            <Grid Background="Transparent">
                                                <PivotHeaderPanel x:Name="StaticHeader" Visibility="Collapsed"/>
                                                <PivotHeaderPanel x:Name="Header">
                                                    <PivotHeaderPanel.RenderTransform>
                                                        <TransformGroup>
                                                            <CompositeTransform x:Name="HeaderTranslateTransform"/>
                                                            <CompositeTransform x:Name="HeaderOffsetTranslateTransform"/>
                                                        </TransformGroup>
                                                    </PivotHeaderPanel.RenderTransform>
                                                </PivotHeaderPanel>
                                            </Grid>
                                        </ContentControl>
                                          <!--CHANGED-->
                                        <Button Grid.Row="1" x:Name="PreviousButton" Background="Transparent" Grid.Column="1" HorizontalAlignment="Left" Height="36" IsTabStop="False" IsEnabled="False" Margin="{ThemeResource PivotNavButtonMargin}" Opacity="0" Template="{StaticResource PreviousTemplate}" UseSystemFocusVisuals="False" VerticalAlignment="Bottom" Width="20"/>
                                          <!--CHANGED-->
                                        <Button Grid.Row="1" x:Name="NextButton" Background="Transparent" Grid.Column="1" HorizontalAlignment="Right" Height="36" IsTabStop="False" IsEnabled="False" Margin="{ThemeResource PivotNavButtonMargin}" Opacity="0" Template="{StaticResource NextTemplate}" UseSystemFocusVisuals="False" VerticalAlignment="Bottom" Width="20"/>
                                          <!--CHANGED-->
                                        <ContentPresenter Grid.Row="1" x:Name="RightHeaderPresenter" ContentTemplate="{TemplateBinding RightHeaderTemplate}" Content="{TemplateBinding RightHeader}" Grid.Column="2" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>

                                    </Grid>
                                </PivotPanel>
                            </ScrollViewer>
                        </Grid>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

然后我定义应用样式的 VisualStates：

 <VisualStateManager.VisualStateGroups>
        <VisualStateGroup x:Name="WindowStates">
            <VisualState x:Name="WideState">
                <VisualState.StateTriggers>
                    <AdaptiveTrigger MinWindowWidth="800" />
                </VisualState.StateTriggers>
                <VisualState.Setters>
                    <Setter Target="MasterPivot.Style" Value="{StaticResource PivotStyleTop}" />
                </VisualState.Setters>
            </VisualState>
            <VisualState x:Name="NarrowState">
                <VisualState.StateTriggers>
                    <AdaptiveTrigger MinWindowWidth="0" />
                </VisualState.StateTriggers>
                <VisualState.Setters>
                    <Setter Target="MasterPivot.Style" Value="{StaticResource PivotStyleBottom}" />
                </VisualState.Setters>
            </VisualState>
        </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>

当我第一次运行应用程序时，我可以看到枢轴 header（我添加了背景颜色以突出显示枢轴控件）

将 window 的大小调整为窄状态会导致触发器执行但会隐藏枢轴 header

header即使在将窗口大小调整回更宽的状态后也不可见。当缓慢调整大小时，我可以看到 headers 在屏幕上闪烁然后再次消失。

这是一个重现问题的示例项目： http://1drv.ms/1N1Nm8q

Answer 1

我必须承认 Pivot 控件的硬编码确实很糟糕，因为如果其模板中的 ScrollViewer 发生更改，所有内部控件都会消失并损坏。（如果您尝试从模板中删除 ScrollViewer，也会发生这种情况）

这是我找到的解决方案：

为主网格和 CurrentStateChanged 事件处理程序添加名称

<Grid x:Name="MainGrid">
    <VisualStateManager.VisualStateGroups>
        <VisualStateGroup x:Name="WindowStates" CurrentStateChanged="WindowStates_CurrentStateChanged">

现在在可视化树中移除和插入：

private async void WindowStates_CurrentStateChanged(object sender, VisualStateChangedEventArgs e)
    {
        MainGrid.Children.Remove(MasterPivot);
        await Task.Delay(100);
        MainGrid.Children.Insert(0, MasterPivot);
    }

这使得重新创建样式和 Pivot 的硬编码代码再次创建正常。

XAML 应用自适应触发器后出现渲染问题

XAML rendering issues after adaptive trigger is applied

xaml

uwp

windows-10-universal