How can I change the TreeView Icon into a folder icon?

Question

I\'m trying to change the icon of my TreeView in a folder icon. Also when it collapses it needs to have an opened folder icon.

My treeview has databound items in it and

Answer 1

Incidentally i did something like this just a few days ago. In my application a folder icon is added in the HierarchicalDataTemplate to those objects which behave like folders, i use a trigger to change the icon based on whether the item is expanded or not, here's the relevant bit of XAML:

    <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 hold the icons for the folder states. IconImageStyleSmall is a style which sets the MaxWidth and MaxHeight of the images to something appropriate.

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Edit: For completion's sake.

<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