Problème masqué avec la barre de défilement XAML ScrollViewer (Silverlight)

Question

J'ai ce problème étrange par lequel le contenu dans une visionneuse de défilement augmente, la visionneuse de défilement montre alors la barre de défilement horizontale. Cependant, la grille dans laquelle se trouve ScrollViewer ne semble pas redimensionner suffisamment pour afficher la barre de défilement.

J'ai isolé le problème dans cet exemple d'application, essentiellement du xaml et du code en retard pour simuler l'augmentation de la taille du contenu.

Notez que la barre de défilement de droite ne s'affiche pas correctement lorsque vous cliquez sur le bouton de redimensionnement. J'ai ajouté un peu de remplissage pour indiquer qu'il est présent mais pas au bon endroit.

Si je supprime la rangée du haut, cela semble fonctionner.

Avez-vous des idées et merci d'avance les gars et les filles?

<UserControl x:Class="SilverlightApplication7.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
mc:Ignorable="d"
>
<Grid 
    ShowGridLines="True" 
    HorizontalAlignment="Stretch" 
    VerticalAlignment="Stretch"
>
    <Grid.RowDefinitions>
        <RowDefinition x:Name="DealHeaderRow" Height="Auto" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition x:Name="DealBarColumn" Width="Auto"></ColumnDefinition>
        <ColumnDefinition x:Name="MarketViewerColumn" Width="Auto"></ColumnDefinition>
        <ColumnDefinition x:Name="DealEditorColumn" Width="*" ></ColumnDefinition>
        <ColumnDefinition x:Name="InfoColumn" Width="Auto"></ColumnDefinition>
    </Grid.ColumnDefinitions>

    <ContentControl 
        x:Name="DealBarRegionContentControl"
        Grid.Row="0"
        Grid.Column="0" 
        Grid.RowSpan="2"
        VerticalContentAlignment="Stretch"
        HorizontalAlignment="Stretch"
        Margin="0">
        <TextBlock Text="DealBarRegion" Width="150" />
    </ContentControl>

    <ContentControl 
        Grid.Row="0"
        Grid.Column="1" 
        Grid.RowSpan="2"
        VerticalContentAlignment="Stretch"
        HorizontalAlignment="Stretch"
        HorizontalContentAlignment="Stretch">
        <Border Background="#FF9AF172">
            <TextBlock Text="MarketViewerRegion"  Width="150"  />
        </Border>
    </ContentControl>

    <ContentControl 
        Grid.Column="2" 
        Grid.ColumnSpan="2"
        Grid.Row="0"
        HorizontalAlignment="Stretch"
        HorizontalContentAlignment="Stretch" >
        <Border Background="#FFC1FC9F">
            <TextBlock Text="DealHeaderRegion"  />
        </Border>
    </ContentControl>

    <ContentControl 
        Grid.Column="2" 
        Grid.Row="1" 
        VerticalAlignment="Top"
        HorizontalContentAlignment="Stretch" 
        VerticalContentAlignment="Stretch">
        <Border Background="MistyRose" >
            <TextBlock Text="DealEditorRegion" />
        </Border>
    </ContentControl>

    <Grid
        Grid.Column="3" 
        Grid.Row="1" 
    >
        <ContentControl 
            x:Name="InfoRegionControl" 
            VerticalContentAlignment="Stretch"
            HorizontalAlignment="Stretch">
            <!-- without the padding here you can't see the scroll bar at all !! Its like the 
            scroll ScrollViewer isn't correctly calculating its width to include the scroll bar,
            or the grid isn't sizing at the points its visible??-->
            <Border Padding="0,0,9,0" MinWidth="200" x:Name="DealInfoControlPlaceHolder">
                <ScrollViewer  
                    HorizontalAlignment="Stretch" 
                    HorizontalContentAlignment="Stretch"
                    VerticalScrollBarVisibility="Auto" 
                    HorizontalScrollBarVisibility="Auto"  
                    >
                    <StackPanel x:Name="ScrollContentPlaceHolder">
                        <Button Click="Button_Click" Content="Rezize Column" x:Name="ResizeButton" />
                    </StackPanel>
                </ScrollViewer>
            </Border>
        </ContentControl>
    </Grid>
</Grid>

Et voici le code derrière:

using System.Windows;
using System.Windows.Controls;

namespace SilverlightApplication7
{
    public partial class MainPage : UserControl
    {
        double _dealInfoControlPlaceHolderHeight = 0;
        double _dealInfoControlPlaceHolderWidth = 0;

        public MainPage()
        {
            InitializeComponent();

            Loaded += (o, e) =>
            {
                // cache the original width and height
                _dealInfoControlPlaceHolderHeight = DealInfoControlPlaceHolder.Height;
                _dealInfoControlPlaceHolderWidth = DealInfoControlPlaceHolder.Width;
            };
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (ScrollContentPlaceHolder.Height == 1200)
            {
                ScrollContentPlaceHolder.Height = _dealInfoControlPlaceHolderHeight;
                ScrollContentPlaceHolder.Width = _dealInfoControlPlaceHolderWidth;
            }
            else
            {
                ScrollContentPlaceHolder.Height = 1200;
                ScrollContentPlaceHolder.Width = 250;
            }
        }
    }
}

Answer 1

Ok, je ne sais pas pourquoi ce qui précède ne fonctionne pas, mais comme solution de contournement, je viens de restructurer la page pour qu'elle se comporte de la même manière. Cela fonctionne:

<UserControl x:Class="SilverlightApplication7.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
mc:Ignorable="d"
>
<Grid 
    ShowGridLines="True" 
    HorizontalAlignment="Stretch" 
    VerticalAlignment="Stretch"
>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition x:Name="DealBarColumn" Width="Auto"></ColumnDefinition>
        <ColumnDefinition x:Name="MarketViewerColumn" Width="Auto"></ColumnDefinition>
        <ColumnDefinition x:Name="DealEditorColumn" Width="*" ></ColumnDefinition>
    </Grid.ColumnDefinitions>

    <ContentControl 
        x:Name="DealBarRegionContentControl"
        Grid.Column="0" 
        VerticalContentAlignment="Stretch"
        HorizontalAlignment="Stretch"
        Margin="0">
        <TextBlock Text="DealBarRegion" Width="150" />
    </ContentControl>

    <ContentControl 
        Grid.Column="1" 
        VerticalContentAlignment="Stretch"
        HorizontalAlignment="Stretch"
        HorizontalContentAlignment="Stretch">
        <Border Background="#FF9AF172">
            <TextBlock Text="MarketViewerRegion"  Width="150"  />
        </Border>
    </ContentControl>

    <Grid
        Grid.Column="2" >
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <ContentControl 
            Grid.Row="0"
            HorizontalAlignment="Stretch"
            HorizontalContentAlignment="Stretch" >
            <Border Background="#FFC1FC9F">
                <TextBlock Text="DealHeaderRegion"  />
            </Border>
        </ContentControl>

        <Grid 
            Grid.Row="1"     
            HorizontalAlignment="Stretch"
            VerticalAlignment="Stretch"
            >
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"></ColumnDefinition>
                <ColumnDefinition Width="Auto"></ColumnDefinition>
            </Grid.ColumnDefinitions>
            <ContentControl 
                Grid.Column="0"
                VerticalAlignment="Top"
                HorizontalContentAlignment="Stretch" 
                VerticalContentAlignment="Stretch">
                <Border Background="MistyRose" >
                    <TextBlock Text="DealEditorRegion" />
                </Border>
            </ContentControl>
            <ContentControl 
                Grid.Column="1"
                x:Name="InfoRegionControl" 
                VerticalContentAlignment="Stretch"
                HorizontalAlignment="Right">
                <!-- without the padding here you can't see the scroll bar at all !! Its like the 
                scroll ScrollViewer isn't correctly calculating its width to include the scroll bar,
                or the grid isn't sizing at the points its visible??-->
                <Border Padding="0,0,9,0" MinWidth="200" x:Name="DealInfoControlPlaceHolder">
                    <ScrollViewer  
                        HorizontalAlignment="Stretch" 
                        HorizontalContentAlignment="Stretch"
                        VerticalScrollBarVisibility="Auto" 
                        HorizontalScrollBarVisibility="Auto"  
                        >
                        <StackPanel x:Name="ScrollContentPlaceHolder">
                            <Button Click="Button_Click" Content="Rezize Column" x:Name="ResizeButton" />
                        </StackPanel>
                    </ScrollViewer>
                </Border>
            </ContentControl>
        </Grid>
    </Grid>
</Grid>