How can I change the TreeView icon to a folder icon?

Question

I am trying to change the icon of my TreeView in a folder icon. Also, when it crashes, it should have an open folder icon.

There are data binding elements in my tree structure, and the code:

<TreeView x:Name="TreeViewCategories" Grid.Row="0" Grid.Column="1" Height="610" HorizontalAlignment="Left" Margin="29,111,0,0" VerticalAlignment="Top" Width="315" BorderThickness="0" Background="Transparent" > <TreeView.ItemTemplate> <HierarchicalDataTemplate ItemsSource="{Binding Items}"> <TextBlock FontSize="20" Text="{Binding Name}" PreviewMouseDown="TextBlock_PreviewMouseDown"/> </HierarchicalDataTemplate> </TreeView.ItemTemplate> </TreeView> 

Also this is how I populate treeview with elements from XML (this is cut from a lot of code:

 private void LoadHospitalXML() { try { FileStream fs = new FileStream("ConfigOrgHospital.xml", FileMode.Open, FileAccess.Read); var xml = XmlReader.Create(fs); rootElement = ConvertHospitalData(xml); this.TreeViewCategories.ItemsSource = null; List<HospitalWrapper> li = new List<HospitalWrapper>(); var hosp = rootElement.Items.FirstOrDefault(); if (hosp != null) { foreach (var i in hosp.Hospital) { li.AddIfNotNull(CreateHospList(i)); } } this.TreeViewCategories.ItemsSource = li; } catch (Exception e) { MessageBox.Show(e.Message); } } private HospitalWrapper CreateHospList(object obj) { var newItem = new HospitalWrapper(); newItem.Context = obj; //Hospital Names// if (obj is HospitalDataHospitalsHospital) { var hosp = (HospitalDataHospitalsHospital)obj; //newItem.Title = "Hospitals"; newItem.Name = hosp.DefaultName; var tmp = new HospitalWrapper(); tmp.Name = "Sites"; tmp.IsTitle = true; if (hosp.Sites != null) foreach (var i in hosp.Sites) { tmp.Items.AddIfNotNull(CreateHospList(i)); } newItem.Items.Add(tmp); tmp = new HospitalWrapper(); tmp.Name = "Specialties"; tmp.IsTitle = true; if (hosp.Deps != null) foreach (var j in hosp.Deps) { tmp.Items.AddIfNotNull(CreateHospList(j)); } newItem.Items.Add(tmp); } } 

Answer 1

By the way, I did something like this just a few days ago. In my application, the icon icon is added to the HierarchicalDataTemplate to those objects that behave like folders, I use a trigger to change the icon depending on whether the item was expanded or not, here is the corresponding XAML bit:

  <HierarchicalDataTemplate DataType="{x:Type data:FeedComposite}" ItemsSource="{Binding Path=Children}"> <StackPanel Orientation="Horizontal" Margin="1"> <StackPanel.Children> <Image> <Image.Style> <Style BasedOn="{StaticResource IconImageStyleSmall}" TargetType="Image"> <Setter Property="Source" Value="{Binding Source={StaticResource Icon_FolderClosed}, Mode=OneTime}"/> <Style.Triggers> <DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=TreeViewItem}, Path=IsExpanded}" Value="True"> <Setter Property="Source" Value="{Binding Source={StaticResource Icon_FolderOpen}, Mode=OneTime}"/> </DataTrigger> </Style.Triggers> </Style> </Image.Style> </Image> <TextBlock Text="{Binding Title}"/> </StackPanel.Children> </StackPanel> </HierarchicalDataTemplate> 

Where {StaticResource Icon_FolderOpen} and {StaticResource Icon_FolderClosed} are BitmapImages that contain icons for folder states. IconImageStyleSmall is a style that sets the MaxWidth and MaxHeight image to something suitable.

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Edit: To achieve the goal.

 <BitmapImage x:Key="Icon_FolderOpen" UriSource="pack://application:,,,/ImageResources/Icons/FolderOpen.ico" /> <BitmapImage x:Key="Icon_FolderClosed" UriSource="pack://application:,,,/ImageResources/Icons/FolderClosed.ico" /> <Style x:Key="IconImageStyleSmall" TargetType="Image"> <Setter Property="MaxWidth" Value="16"/> <Setter Property="MaxHeight" Value="16"/> <Setter Property="Margin" Value="1"/> </Style> 

Icons used