Good morning. I have a class with data derived from InotifyPropertyChange. The data come from a background thread, which searches for files with certain extension in certain locations. Public property of the class reacts to an event OnPropertyChange by updating data in a separate thread. Besides, there are described in XAML TreeView, based on HierarhicalDataTemplates. Each TextBlock inside templates supplied ItemsSource = "{Binding FoundFilePaths, Mode = OneWay, NotifyOnTargetUpdated = True}".

enter code here

                <HierarchicalDataTemplate  DataType = "{x:Type lightvedo:FilesInfoStore}"  ItemsSource="{Binding FoundFilePaths, Mode=OneWay, NotifyOnTargetUpdated=True}">
                    <!--????? ??????????? ???? ??????-->
                    <StackPanel x:Name ="TreeNodeStackPanel" Orientation="Horizontal">
                        <TextBlock Margin="5,5,5,5" TargetUpdated="TextBlockExtensions_TargetUpdated">
         <TextBlock.Text>
          <MultiBinding StringFormat="Files with Extension  {0}">
           <Binding Path="FileExtension"/>
          </MultiBinding>
         </TextBlock.Text>
                        </TextBlock>
                        <Button x:Name="OpenFolderForThisFiles" Click="OnOpenFolderForThisFiles_Click" Margin="5, 3, 5, 3" Width="22" Background="Transparent" BorderBrush="Transparent" BorderThickness="0.5">
                            <Image Source="images\Folder.png" Height="16" Width="20" >
                            </Image>
                        </Button>
                    </StackPanel>
                </HierarchicalDataTemplate>
                <HierarchicalDataTemplate DataType="{x:Type lightvedo:FilePathsStore}">

                    <TextBlock Text="{Binding FilePaths, Mode=OneWay, NotifyOnTargetUpdated=True}" TargetUpdated="OnTreeViewNodeChildren_Update" />
                </HierarchicalDataTemplate>
            </TreeView.Resources>
            <TreeView.RenderTransform>
                <TransformGroup>
                    <ScaleTransform/>
                    <SkewTransform AngleX="-0.083"/>
                    <RotateTransform/>
                    <TranslateTransform X="-0.249"/>
                </TransformGroup>
            </TreeView.RenderTransform>
            <TreeView.BorderBrush>
                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                    <GradientStop Color="#FF74591F" Offset="0" />
                    <GradientStop Color="#FF9F7721" Offset="1" />
                    <GradientStop Color="#FFD9B972" Offset="0.49" />
                </LinearGradientBrush>
            </TreeView.BorderBrush>
        </TreeView>

Q: Why is the data from a class derived from INotifyPropertyChange does not affect the display of tree items. Do I understand: The interface will make INotifyPropertyChange be automatically redrawn TreeViewItems or do I need to manually carry out this operation? Currently TreeViewItems not updated and PropertyChamged always null. A feeling that no subscribers to the event OnPropertyChanged.