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Editorial Team
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Asked: 2026-06-05T10:23:03+00:00

I have a listview for which I want to format several fields from a

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I have a listview for which I want to format several fields from a populating object. Initially I created a data template which threw an InvalidOperationException with a blank page and no indication of the cause of the exception. I found an article on CodeProject and I have the datatemplate now embedded in a Setter definition:

<UserControl x:Class="Servpro.Framework.ViewerModule.Views.MenuView"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" 
         d:DesignHeight="580" d:DesignWidth="210">
<UserControl.Resources>
    <Style TargetType="ListView">
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <DataTemplate>
                    <StackPanel Orientation="Vertical">
                        <TextBlock 
                            Background="Transparent"
                            Foreground="Black" 
                            FontSize="12" 
                            Text="{Binding Path=CurrentEvent.EventTypeName, Mode=OneWay}" />
                        <TextBlock 
                            Background="Transparent"
                            Foreground="Black" 
                            FontSize="12" 
                            Text="{Binding Path=CurrentEvent.EventMessage, Mode=OneWay}" />
                        <StackPanel Orientation="Horizontal">
                            <TextBlock 
                                Background="Transparent" 
                                Foreground="Black" 
                                FontSize="8" 
                                Text="{Binding Path=CurrentEvent.EventLoggedOn, Mode=OneWay}"
                                Margin="0,0,10,0" />
                            <TextBlock
                                Background="Transparent" 
                                Foreground="Black" 
                                FontSize="8"
                                Text="{Binding Path=CurrentEvent.Program, Mode=OneWay}" />
                            <TextBlock 
                                Background="Transparent" 
                                Foreground="Black" 
                                FontSize="8"
                                Text=":" />
                            <TextBlock 
                                Background="Transparent" 
                                Foreground="Black" 
                                FontSize="8" 
                                Text="{Binding Path=CurrentEvent.Method, Mode=OneWay}" />
                        </StackPanel>
                    </StackPanel>
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</UserControl.Resources>
<Grid Margin="4">
    <ListView 
        ItemsSource="{Binding Path=EventList, Mode=OneWay}" 
        Height="568" VerticalAlignment="Top" 
        Width="201" HorizontalAlignment="Left" 
        Margin="4" >
        <Border CornerRadius="11" />
        <ListView.BorderBrush >
            <SolidColorBrush Color="#99FFFFFF" Opacity="0" />
        </ListView.BorderBrush>
        <ListView.Background>
            <SolidColorBrush Color="#99FFFFFF" Opacity="0"/>
        </ListView.Background>
    </ListView>
</Grid>

With the definition ASIS I now get a runtime exception and it is finally pointing at the XAML. But I still do not understand why I’m getting it. The exception:

‘Add value to collection of type ‘System.Windows.Controls.ItemCollection’ threw an exception.’ Line number ’55’ and line position ’13’.

It has the inner exception:

{“Operation is not valid while ItemsSource is in use. Access and modify elements with ItemsControl.ItemsSource instead.”}

I’m clearly using ItemsSource so why am I getting this exception??

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1 Answer

  1. Editorial Team

    It turned out that the setting of the border and background brushes in the main line of the XAML was the issue. I removed them and use Setter.Property in my DataTemplate and the application runs now.

    So for future designs: when defining the look of a ListView with a data template, it is important that styling remain with the data template. My final page design ended up to be significantly different as I added some formatting following this blog

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