XAML ScrollViewer scroll bar hidden issue (Silverlight) - wpf

Question

I’ve got this strange problem whereby the content within a scroll viewer increases in size, the scroll viewer then shows is horizontal scroll bar. However the grid the ScrollViewer is ultimately within doesn’t seem to resize enough to show the scroll bar.
I’ve isolated the problem in this sample app, basically some xaml and some code behind to simulate the content size increase.
Note how the right scroll bar is not correctly showing when you click the resize button, I’ve added some padding to show that its there but not in the correct place.
If I remove the top row it seems to work.
Any ideas and thanks in advance guys and girls?
<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>
And here is the code behind:
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 I don’t know why the above doesn’t work, but as a workaround I just restructure the page so its behaves the same. That works:
<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>