在Microsoft Store App中垂直滚动后，GridView数据与Header重叠

Question

我有一个GridView，如下所示：

<Page
x:Name="pageRoot"
x:Class="View.ServiceModule"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:View"
xmlns:common="using:View.Common"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Page.Resources>
    <CollectionViewSource
        x:Name="groupedItemsViewSource"
        Source="{Binding ServiceTasksFiltered}"
        IsSourceGrouped="true"
        ItemsPath="ServiceTasksFiltered">
    </CollectionViewSource>
</Page.Resources>

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid.ChildrenTransitions>
        <TransitionCollection>
            <EntranceThemeTransition/>
        </TransitionCollection>
    </Grid.ChildrenTransitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="140"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>


    <GridView
        Visibility="Collapsed"
        x:Name="serviceTasksFilteredGridView"
        TabIndex="1"
        Grid.RowSpan="2"
        Padding="116,136,116,46"
        ItemsSource="{Binding ServiceTasksFiltered, Mode=TwoWay}"
        SelectionMode="None"
        IsSwipeEnabled="false"
        IsItemClickEnabled="true"
        ScrollViewer.VerticalScrollMode="Auto"
        ScrollViewer.VerticalScrollBarVisibility="Auto"
        VerticalAlignment="Top">
        <GridView.ItemContainerStyle>
            <Style TargetType="GridViewItem">
                <Setter Property="HorizontalAlignment" Value="Stretch"/>
                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            </Style>
        </GridView.ItemContainerStyle>
        <GridView.ItemsPanel>
            <ItemsPanelTemplate>
                <StackPanel HorizontalAlignment="Stretch"/>
            </ItemsPanelTemplate>
        </GridView.ItemsPanel>
        <GridView.Header>
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="100"></ColumnDefinition>
                    <ColumnDefinition Width="200"></ColumnDefinition>
                    <ColumnDefinition Width="500"></ColumnDefinition>
                    <ColumnDefinition Width="300"></ColumnDefinition>
                    <ColumnDefinition Width="300"></ColumnDefinition>
                </Grid.ColumnDefinitions>
                <TextBlock Text="Debitornr." TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
                <TextBlock Grid.Column="1" Text="Name" TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
                <TextBlock Grid.Column="2" Text="Belegnr." TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
                <TextBlock Grid.Column="3" Text="Reaktionsdatum" TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
                <TextBlock Grid.Column="4" Text="Priorität" TextWrapping="Wrap" FontSize="24" FontWeight="Bold"/>
            </Grid>
        </GridView.Header>
        <GridView.ItemTemplate>
            <DataTemplate>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="100"></ColumnDefinition>
                        <ColumnDefinition Width="200"></ColumnDefinition>
                        <ColumnDefinition Width="500"></ColumnDefinition>
                        <ColumnDefinition Width="300"></ColumnDefinition>
                        <ColumnDefinition Width="300"></ColumnDefinition>
                    </Grid.ColumnDefinitions>
                    <TextBlock Text="{Binding CustomerNo}" TextWrapping="Wrap" FontSize="20"/>
                    <TextBlock Grid.Column="1" Text="{Binding CustomerName}" TextWrapping="Wrap" FontSize="20"/>
                    <TextBlock Grid.Column="2" Text="{Binding DocumentNo}" TextWrapping="Wrap" FontSize="20"/>
                    <TextBlock Grid.Column="3" Text="{Binding ResponseDateDisplay}" TextWrapping="Wrap" FontSize="20"/>
                    <TextBlock Grid.Column="4" Text="{Binding PriorityDisplay}" TextWrapping="Wrap" FontSize="20"/>
                </Grid>
            </DataTemplate>
        </GridView.ItemTemplate>
    </GridView>

    <!-- Back button and page title -->
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="120"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Button x:Name="backButton" Margin="39,59,39,0" 
                    Click="BackButton"
                    Style="{StaticResource NavigationBackButtonNormalStyle}"
                    VerticalAlignment="Top"
                    AutomationProperties.Name="Back"
                    AutomationProperties.AutomationId="BackButton"
                    AutomationProperties.ItemType="Navigation Button"/>
        <TextBlock x:Name="pageTitle" Text="Serviceaufgaben" Style="{StaticResource HeaderTextBlockStyle}" Grid.Column="1" 
                    IsHitTestVisible="false" TextWrapping="NoWrap" VerticalAlignment="Bottom" Margin="0,0,30,40"/>
    </Grid>
</Grid>

当我尝试向下滚动以显示底行时，顶行将向上移动而不是消失。请参阅下图以获得更好的描述：

GridView with wrong scrolling settings

正如您所看到的，GridView向下滚动，行位于页面标题的后面。我需要它们消失。

非常感谢任何帮助。