ItemSource of Listbox is not updated on item change-CodePudding

In my WPF application I have ListBox which contains a collection of items. One item can be added when a button is clicked and it is selected in the opened dialogue. As soon as a item is selected the dialogue closes and the item's image and name should be displayed in my ListBox. Unfortunately the Listbox does not update and nothing changes.

Usercontrol with Listbox:

<ListBox ItemsSource="{Binding BlButtonCollection, UpdateSourceTrigger=PropertyChanged}" VerticalContentAlignment="Stretch" SelectedItem="{Binding SelectedSticker}"
                     HorizontalContentAlignment="Stretch" ItemContainerStyle="{StaticResource ListBoxItemStyle}">
                <ListBox.Resources>
                    <viewmodels1:BindingProxy x:Key="ProxyElement" Data="{Binding}" />
                </ListBox.Resources>
                <ListBox.ItemsPanel>
                    <ItemsPanelTemplate>
                        <UniformGrid Columns="4" Rows="10"/>
                    </ItemsPanelTemplate>
                </ListBox.ItemsPanel>
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <Border BorderBrush="Black" BorderThickness="1">
                            <Grid x:Name="f">
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="5*"/>
                                    <RowDefinition Height="*"/>
                                </Grid.RowDefinitions>
                                <Button x:Name="btnSelectArticle" Background="Transparent" Grid.RowSpan="2" BorderThickness="0" 
                                        Command="{Binding DataContext.ButtonClicked,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBox}}}"/>
                                <Image Height="1.5cm" HorizontalAlignment="Center" Source="{Binding ItemImage.ImageUrl, Converter={StaticResource ImageFormatConverter}}"/>
                                <TextBlock Text="{Binding ItemName}" Width="4cm" Height="0.8cm" TextWrapping="Wrap" Grid.Row="1" HorizontalAlignment="Center"/>
                            </Grid>
                        </Border>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

Controls with ListBoxes in main window:

<formats:OneXTwo x:Name="oneXTwo" BlButtonCollection="{Binding BlButtons_2}" IsBlVisible="Visible" Visibility="{Binding Are2StickersVisible}" 
                                 ButtonClicked="{Binding BlStickerButtonClickedCommand}"/>
                <formats:ThreeXEight x:Name="threeXEight" BlButtonCollection="{Binding BlButtons_24}" IsBlVisible="Visible" Visibility="{Binding Are24StickersVisible}" 
                                     ButtonClicked="{Binding BlStickerButtonClickedCommand}"/>
                <formats:FourXTen x:Name="fourXTen" BlButtonCollection="{Binding BlButtons_40, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" IsBlVisible="Visible" Visibility="{Binding Are40StickersVisible}" 
                                  ButtonClicked="{Binding BlStickerButtonClickedCommand}" SelectedSticker="{Binding SelectedBlSticker, Mode=TwoWay}" />

I should mention that I have three different formats and each format is a own user-control. Therfore, they are displayed in a shell-view and based on a ComboBox selection one format is displayed. If I am running the application, select a image nothing happens, but if I change the bound value of the textblock in the list view and switch it back to 'Itemname' the Image and Name are displayed.

CodePudding user response：

Have you set the DataContext to a specific ViewModel?
ObservableCollection can only ensure the add/remove operation for items that can be updated to the UI. If you want to the item property to notify the UI, you should override the setter of the property and implement the IPropertyChangedNotify.