Listbox content not dynamically re-sizing when Listbox size changes

Question

I've seen quite a few people asking this question and i feel like my question is slightly different. I have a listbox that holds a series of identical custom made user controls. These controls are added to the listbox at runtime. Now i currently have my listbox items resizing themselves properly upon first creation and insertion into the control.

Here is the strange part. If I resize the listbox the controls that have been visible previously are not resized to the new listbox width. In other words if i add 12 controls and the box only shows 4 (the rest are hidden by a scrollbar) then if i resize the box the first 4 controls will still be the original width and if i scroll then the other 8 will be the correct size. Also if i manipulate the list items in any way they resize themselves to the proper width automatically. SEE EDIT2

I've tried attaching to the sizeChanged event and issuing the following on both the listbox and the items but it has had no effect. I think i need to find some way of resetting the layout information for the listbox items but i can't find the command.

item.InvalidateArrange();
item.InvalidateMeasure();
Layers.UpdateLayout();
item.UpdateLayout();

I think this has something to do with the items i'm adding because even if i detach the items from the lisbox and then attach them they remain the wrong width.

Here is my listbox code:

<ListBox x:Name="Layers" VerticalContentAlignment="Top" Margin="0,17,0,0" BorderThickness="0,1,0,0" HorizontalContentAlignment="Stretch" SizeChanged="Layers_SizeChanged">
                        <ListBox.ItemContainerStyle>
                            <Style TargetType="ListBoxItem">
                                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
                            </Style>
                        </ListBox.ItemContainerStyle>
                    </ListBox>

Here is the code for my items

<UserControl x:Class="ListOverlayItem"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:data="clr-namespace:Data"
HorizontalContentAlignment="Stretch">

<UserControl.Resources>
    <data:Translator x:Key="translatorString" />
</UserControl.Resources>

<Border BorderBrush="Silver" BorderThickness="0,0,0,0" Name="border1" HorizontalAlignment="Stretch">
    <Grid x:Name="layout" HorizontalAlignment="Stretch">
        <Grid.RowDefinitions>
            <RowDefinition Height="19"/>
            <RowDefinition Height="25" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="20" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="60" />
        </Grid.ColumnDefinitions>
        <!-- Column 0 -->
        <ScrollBar Name="arrangeIcon" FlowDirection="LeftToRight" Maximum="10" SmallChange="1" Value="5" Grid.Column="0" Grid.Row="0" Grid.RowSpan="2"/>

        <!-- Column 1 -->
        <Slider  Name="OverlayOpacity" Height="25" Grid.Column="1" Margin="6,0,0,0" Grid.Row="1"  Maximum="1" LargeChange="0.1" ValueChanged="OverlayOpacity_ValueChanged"/>
        <TextBlock x:Name="OverlayName" Text="{Binding Path=LocationName}" Foreground="#FFF08D2D" Margin="10,2,0,0" Grid.Column="1" FontSize="12" Height="18" VerticalAlignment="Top" />

        <!-- Column 3 -->
        <Button Name="SettingsButton" Grid.Column="3" Content="{Binding TRK_OV_Settings, Source={StaticResource translatorString}}" VerticalAlignment="Center" Click="SettingsButton_Click" />
        <CheckBox x:Name="OverlayEnabled" FlowDirection="LeftToRight" Grid.Column="2" DataContext="{Binding}" HorizontalAlignment="Right" VerticalAlignment="Center" Grid.RowSpan="2" Checked="OverlayEnabled_Checked" Unchecked="OverlayEnabled_Unchecked" />
        <TextBlock Name="percentage" Text="100%" FontSize="9" TextAlignment="Right" Grid.Column="2" Grid.Row="1" VerticalAlignment="Center" Margin="2,6,26,6" MinWidth="30"/>
    </Grid>
</Border>

Again it seems like my UserControl is correctly able to scale itself its just not getting the command to do so when the parent container is resized.

EDIT: Whoops, removed the WPF tag because it was incorrectly added. I think i've got it down to slider being the culprit. If i set the slider to a fixed size instead of 'stretch' then the item correctly scales just fine. So the question now is how do i force the slider to resize itself.

EDIT2: I know what is causing the issue but i don't know how to solve it. What is happening is the slider that i have in my user control will NOT resize along with the rest of the control unless i change the value of the slider during the resize. The instant i change its value even a fraction it resizes itself automatically. How can i force it to resize?

Answer 1

I determined that the slider was causing the issue and i tried many ways to force the slider to re-draw when it needed to but i was unsuccessful. My final solution was to remove the slider entirely. Works fine now.