WPF Dynamic Resource Not Updating when inside data template

Question

I am trying to setup a system in a WPF app where the user can select a different theme and the UI updates. To achieve this I am removing one resource dictionary and merging in another one.

Everything is working fine except one scenario.

I have some pages that define a datatemplate. In the datatemplate is a rectangle that is bound to a string property on the viewmodel (using Caliburn.Micro) and I have a converter that converts the string into a drawingbrush (it finds it from the resources).

The problem is that the dynamicresource in the drawingbrush (the color) will not update.

Every other instance of rectangle I have bound the same way (not in a datatemplate) the color of the drawing brush updates perfectly. Only when inside the datatemplate does this problem occur.

Here is a sample of the data template on a view

<DataTemplate x:Key="ListBoxItemTemplate">
        <Border Style="{DynamicResource EntitySelectListBox}">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <Rectangle Grid.Column="0" Fill="{Binding IconName, Converter={converters:StringToResourceConverter}}" Width="50" Height="50" Margin="5" ToolTip="{Binding ToolTip}" />

                <TextBlock FontFamily="Segoe WP"
                           FontWeight="Light"
                           FontSize="22"
                           Grid.Column="1"
                           VerticalAlignment="Center"
                           HorizontalAlignment="Center"
                           Text="{Binding ButtonText}" />
            </Grid>
        </Border>
    </DataTemplate>

Here is an example of a drawing brush that has a dynamicresource for the color:

<DrawingBrush x:Key="BankIcon" Viewbox="0,0,442,442" ViewboxUnits="Absolute">
    <DrawingBrush.Drawing>
        <DrawingGroup>
            <DrawingGroup.Transform>
                <MatrixTransform Matrix="9.20833333333333,0,0,9.20833333333333,0,0"/>
            </DrawingGroup.Transform>
            <DrawingGroup>
                <DrawingGroup.Transform>
                    <MatrixTransform Matrix="1,0,0,1,0,2.04885336170188"/>
                </DrawingGroup.Transform>
                <GeometryDrawing Brush="{DynamicResource SecondaryText}" Geometry="M32.015748,33.342608 L46.283901,33.342608 C47.231779,33.342608 48,34.111116 48,35.061416 L48,40.968297 29.109026,40.968297 C31.057581,39.645195 32.207827,37.567466 32.207827,35.105579 32.207827,34.463728 32.135616,33.879828 32.015748,33.342608 z M1.7188548,33.342608 L21.193252,33.342608 C21.734045,33.580305 22.220392,33.759667 22.584643,33.892346 24.90359,34.727827 24.90359,35.253493 24.90359,35.449457 24.90359,35.986481 23.92294,36.182345 23.261798,36.182345 21.415607,36.182345 19.949486,35.468384 19.243114,35.041909 L17.321123,33.889921 15.507445,40.263165 16.585441,40.951892 0,40.968297 0,35.061416 C8.7927075E-13,34.111116 0.76985754,33.342608 1.7188548,33.342608 z M22.790523,18.230994 L25.366021,18.230994 25.366021,21.121156 C27.345029,21.183175 28.700861,21.687368 29.703128,22.191564 L28.856339,25.079107 C28.100782,24.702539 26.716707,23.982205 24.582318,23.982205 22.381153,23.982205 21.594926,25.110746 21.594926,26.179891 21.594926,27.467599 22.72608,28.221998 25.431822,29.259503 28.949705,30.578852 30.489161,32.27603 30.489161,35.105438 30.489161,37.771993 28.636319,40.099727 25.209281,40.667104 L25.209281,43.902294 22.602338,43.902294 22.602338,40.855485 C20.623328,40.792207 18.644319,40.22619 17.510837,39.502072 L18.362478,36.519611 C19.618635,37.270223 21.344919,37.898937 23.261813,37.898937 25.271298,37.898937 26.620819,36.927818 26.620819,35.449302 26.620819,34.003588 25.522762,33.125251 23.167186,32.27603 19.901545,31.081883 17.733186,29.541929 17.733186,26.651183 17.733186,23.9494 19.618635,21.844013 22.790523,21.279064 z M40.239403,16.937238 L44.995147,16.937238 44.995147,31.067614 40.239403,31.067614 z M32.794241,16.937238 L37.545128,16.937238 37.545128,31.067614 32.794241,31.067614 z M10.453898,16.937238 L15.205758,16.937238 15.205758,31.067614 10.453898,31.067614 z M3.0077641,16.937238 L7.7625359,16.937238 7.7625359,31.067614 3.0077641,31.067614 z M23.952052,0 L24.047946,0.0024883747 C24.709093,0.017653378 25.175256,0.11243361 26.113014,0.68999864 L48,14.939825 24.047946,14.939825 23.952052,14.939825 0,14.939825 21.885821,0.68999864 C22.824745,0.11243361 23.292458,0.017653378 23.952052,0.0024883747 z"/>
            </DrawingGroup>
        </DrawingGroup>
    </DrawingBrush.Drawing>
</DrawingBrush>

Here is a resource dictionary that imports a couple other resource dictionarys. One for styles and one for the vectoricons (they are shared between the skins).

ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                x:Class="SixtenLabs.CashFlow.Client.Skins.Monochrome">

<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="/Resources/CommonStyles.xaml"/>
    <ResourceDictionary Source="/Resources/VectorIcons.xaml"/>

I have tried moving various parts around to different places (app.xaml, window.resources) to no avail. Any ideas would be appreciated.

Thanks.

Answer 1

Try turning off virtualization in your ListBox as you may be recycling containers and the containers wont allways honour changes in DynamicResource bindings.

<ListBox VirtualizingStackPanel.IsVirtualizing="False"
         VirtualizingStackPanel.VirtualizationMode="Standard" />