我目前正在开发一个WinUI 3应用程序，我试图在ScrollViewer的上方和下方设置一个StackPanel，它将始终可见（不取决于屏幕的大小或ScrollViewer中的元素）：

<Grid Margin="30,30,30,30">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
                
    <StackPanel Orientation="Horizontal" Grid.Row="0">
        <TextBlock Name="projectNumber" Text="Project Number" Width="100" Margin="10,10,10,10" TextAlignment="Center"/>
        <TextBlock Name="taskName" Text="Task" Width="750" Margin="10,10,10,10" TextAlignment="Center"/>
        <TextBlock Name="dueDate" Text="Due Date" Width="100" Margin="10,10,10,10" TextAlignment="Center"/>
        <TextBlock Name="assignedBy"  Text="Assigned By" Width="100" Margin="10,10,10,10" TextAlignment="Center"/>
    </StackPanel>
    <Line Name="dividerLine" Stroke="DimGray" X1="0" Y1="0" X2="1130" Y2="0" Grid.Row="1"/>
    <ScrollViewer Name="scrollViewer" Grid.Row="2">
        <StackPanel>
            <ListView Name="tasksPanel" VerticalAlignment="Top" HorizontalAlignment="Left"/>
            <ListView Name="completeTasksPanel" VerticalAlignment="Top" HorizontalAlignment="Left"/>
        </StackPanel>
    </ScrollViewer>
    <StackPanel Orientation="Horizontal" Margin="0,10,0,10" Grid.Row="3">
        <TextBox/>
        <TextBox/>
        <TextBox/>
    </StackPanel>
</Grid>

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但是，ScrollViewer元素不会根据屏幕设置其高度，相反，它将占用与内部元素相同的空间。我还尝试将Grid.RowDefinitions设置为设置高度，而不是Auto，但没有区别：

<RowDefinition Height="50"/>
<RowDefinition Height="3"/>
<RowDefinition Height="*"/>
<RowDefinition Height="50"/>

型