WPF Treeview Binding Problem

Question

Evening,

My Continents are displayed in the treeview in this case, and in the second piece of code my country's are displayed but i cant put both together, can somebody help.

Thanks
Madaxe

                            <TreeView ItemsSource="{Binding ContinentModels}"  Name="Tvw_ContinentsCountrys" Margin="2,2,2,2" Background="#FFFFECEC">
                                <TreeView.ItemTemplate>
                                    <HierarchicalDataTemplate ItemsSource="{Binding continentName}">
                                        <Label Content="{Binding continentName}"/>
                                        <HierarchicalDataTemplate.ItemTemplate>
                                            <HierarchicalDataTemplate ItemsSource="{Binding Countrys}">
                                                <TextBlock Text="{Binding countryName}" />
                                            </HierarchicalDataTemplate>
                                        </HierarchicalDataTemplate.ItemTemplate>
                                    </HierarchicalDataTemplate>
                                </TreeView.ItemTemplate>
                            </TreeView>

<TreeView ItemsSource="{Binding ContinentModels}"  Name="Tvw_ContinentsCountrys" Margin="2,2,2,2" Background="#FFFFECEC">
    <TreeView.ItemTemplate>
        <HierarchicalDataTemplate ItemsSource="{Binding Countrys}">
            <TextBlock Text="{Binding countryName}" />
        </HierarchicalDataTemplate>
    </TreeView.ItemTemplate>
</TreeView>

Answer 1

my data context for the treeview is being set on the cs side i moved it to the tree view but im getting an error on the DataType="{x:Type local:Continent}"

section why?

Thanks

Madaxe

                            <TreeView DataContext="_CountryImplementation.ContinentImplementation" ItemsSource="{Binding ContinentModels}"  Name="Tvw_ContinentsCountrys" Margin="2,2,2,2" Background="#FFFFECEC">

                                <TreeView.Resources>
                                    <HierarchicalDataTemplate DataType="{x:Type local:Continent}" ItemsSource="{Binding Countries}">
                                        <TextBlock Text="{Binding ContinentName}"/>
                                    </HierarchicalDataTemplate>
                                </TreeView.Resources>

                            </TreeView>

Answer 2

That did it thanks for you patience

<Window x:Class="TestApplication.Tutorial.DataTypesWindow" 
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:Tutorial="clr-namespace:TestApplication.Tutorial"
           xmlns:local="clr-namespace:Infrastructure;assembly=Infrastructure"
           Title="Objects of arbitrary classes" Height="352" Width="239">

    <Grid>
        <TreeView ItemsSource="{Binding ContinentModels}"  Name="Tvw_ContinentsCountrys" Margin="2,2,2,2" Background="#FFFFECEC">
            <TreeView.Resources>
                <HierarchicalDataTemplate DataType="{x:Type local:ContinentModel}" ItemsSource="{Binding Countrys}">
                    <TextBlock Text="{Binding ContinentName}"/>
                </HierarchicalDataTemplate>
                <HierarchicalDataTemplate DataType="{x:Type local:CountryModel}">
                    <TextBlock Text="{Binding CountryName}"/>
                </HierarchicalDataTemplate>
            </TreeView.Resources>
        </TreeView>
    </Grid>
</Window>

Answer 3

Hi, set HierarchicalDataTemplate for each type of node like in following demo.

XAML:

<Window x:Class="WpfApp1.Window17"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp17"
        mc:Ignorable="d"
        Title="Window17" Height="450" Width="800">
  <Window.DataContext>
    <local:ViewModel/>
  </Window.DataContext>
    <Grid>
    <TreeView ItemsSource="{Binding ContinentModels}">
      <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type local:Continent}" ItemsSource="{Binding Countries}">
          <TextBlock Text="{Binding ContinentName}"/>
        </HierarchicalDataTemplate>
        <HierarchicalDataTemplate DataType="{x:Type local:Country}">
          <TextBlock Text="{Binding CountryName}"/>
        </HierarchicalDataTemplate>  
      </TreeView.Resources>
    </TreeView>
    </Grid>
</Window>

and classes:

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows;
using System.Windows.Data;

namespace WpfApp17
{
  public class ViewModel
  {
    public ViewModel()
    {
      LoadData();
    }
    CollectionViewSource cvs = new CollectionViewSource();
    private ObservableCollection<Continent> col = new ObservableCollection<Continent>();
    public ICollectionView ContinentModels { get => cvs.View; }

    // gerate demo data
    private void LoadData()
    {
      for (int i = 1; i < 10; i++)
      {
        Continent c = new Continent() { ContinentName = $"Continent {i}" };
        col.Add(c);
        for (int k = 1; k < 10; k++) c.Countries.Add(new Country() { CountryName = $"Country {i * 10 + k}" });
      }
      cvs.Source = col;
    }
  }
  public class Continent
  {
    public string ContinentName { get; set; }
    public ObservableCollection<Country> Countries { get; set; } = new ObservableCollection<Country>();
  }
  public class Country
  {
    public string CountryName { get; set; }
  }
}

Answer 4

so my solution structure i have at the moment is as follows, so i guess my view model is my implementation.  When i try to replicate your solution i have problems with the DataType="{x:Type local:Continent}" so i don't believe my view model is local?
thanks
Madaxe
Solution
         ImplementationProject
                      ContinentsImplementation
                                ContinentsObservableCollection
                                          ContinentObject
                                                 ObjectID
                                                 ContinentName
                                                 CountryList
                                                        CountryObject
                                                               ObjectID
                                                                CountryName
         InfrastructureProject
                     ModelsFolder
                                ContinentModel
                                CountryModel
         UserInterfacesProject
                         WPFUI