Developing checkboxes in databound WPF treeview leafs - wpf

Question

I have the next WPF treeview:
<TreeView HorizontalAlignment="Left" Margin="6,0,0,32" Name="tvProductos" Width="158">
<TreeViewItem Header="Securities" IsExpanded="True" FontWeight="Bold">
<TreeViewItem Header="Country" Name="Country" FontWeight="Normal" />
<TreeViewItem Header="Currency" Name="Currency" FontWeight="Normal" />
<TreeViewItem Header="Type" Name="Type" FontWeight="Normal" />
<TreeViewItem Header="ISIN" Name="ISIN" FontWeight="Normal" />
<TreeViewItem Header="Description" Name="Description" FontWeight="Normal" />
</TreeViewItem>
<TreeViewItem Header="Issuer" IsExpanded="True" FontWeight="Bold">
<TreeViewItem Header="Name" Name="IssuerName" FontWeight="Normal" />
<TreeViewItem Header="Type" Name="IssuerType" FontWeight="Normal" />
<TreeViewItem Header="Market" Name="IssuerMarket" FontWeight="Normal" />
</TreeViewItem>
</TreeView>
This structure is fixed. Then I bind low level TreeViewItems using code like this:
Country.ItemsSource = (from d in db.PAISES
join p in db.PRODUCTOS on d.IDPAIS equals p.IDPAIS
select d.NOMBREPAIS).Distinct();
Currency.ItemsSource = (from d in db.DIVISAS
join p in db.PRODUCTOS on d.IDDIVISA equals p.IDDIVISA
select d.NOMBREDIVISA).Distinct();
Type.ItemsSource = (from d in db.TIPOSPRODUCTO
join p in db.PRODUCTOS on d.IDTIPOPRODUCTO equals p.IDTIPOPRODUCTO
select d.NOMBRETIPOPRODUCTO).Distinct();
...
The problem is that I need to add one checkbox on each node (low and high level). I have been looking for a solution and the best one is using HierarchicalDataTemplate. But I never found a example with fixed and dynamic nodes at same time. I tried with several examples but I couldn't solve it.
Can you help me on this?
Thank you in advance.
Kind Regards.

Answer 1

The way I'd do it is using a helper class that represents the items that can be checked (some would call it a "view model"):
public class SelectableItem
{
public bool IsSelected { get; set; }
public string Label { get; set; }
}
This allows you to specify a DataTemplate for this specific type:
<TreeView HorizontalAlignment="Left" Margin="6,0,0,32" Name="tvProductos" Width="158">
<TreeView.Resources>
<DataTemplate DataType="{x:Type local:SelectableItem}" xmlns:local="clr-namespace:WpfApplication1">
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}" />
<TextBlock Text="{Binding Label}" />
</StackPanel>
</DataTemplate>
</TreeView.Resources>
<TreeViewItem Header="Securities" IsExpanded="True" FontWeight="Bold">
<TreeViewItem Header="Country" Name="Country" FontWeight="Normal" />
<TreeViewItem Header="Currency" Name="Currency" FontWeight="Normal" />
<TreeViewItem Header="Type" Name="Type" FontWeight="Normal" />
<TreeViewItem Header="ISIN" Name="ISIN" FontWeight="Normal" />
<TreeViewItem Header="Description" Name="Description" FontWeight="Normal" />
</TreeViewItem>
<TreeViewItem Header="Issuer" IsExpanded="True" FontWeight="Bold">
<TreeViewItem Header="Name" Name="IssuerName" FontWeight="Normal" />
<TreeViewItem Header="Type" Name="IssuerType" FontWeight="Normal" />
<TreeViewItem Header="Market" Name="IssuerMarket" FontWeight="Normal" />
</TreeViewItem>
</TreeView>
All you need to do is modify slightly your data sources:
Country.ItemsSource = (from d in db.PAISES
join p in db.PRODUCTOS on d.IDPAIS equals p.IDPAIS
select new SelectableItem { Label = d.NOMBREPAIS }).Distinct();
And that should do the trick.