“Cascade” binding on ObservableCollection, containing other ObservableCollection

Question

I have a project where I need to display a list of contract (Class Affaire). Each contract has a list of phases (Class Phase). I display each of them in 2 different ListView usi

Answer 1

Here is the example, based on your source, that will handle all stuff. a View Models:

using System.Collections.ObjectModel; using System.ComponentModel;

namespace WpfApp2 { public class BaseViewModel : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged;

    public void NotifyPropertyChanged(string nomPropriete)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(nomPropriete));
    }
}

public class Contexte : BaseViewModel
{
    private Affaire _selectedAffaire;
    private Phase _selectedPhase;
    public ObservableCollection<Affaire> ListeDesAffaires { get; set; }

    public Affaire SelectedAffaire
    {
        get { return _selectedAffaire; }
        set
        {
            _selectedAffaire = value;
            this.NotifyPropertyChanged("SelectedAffaire");
        }
    }

    public Phase SelectedPhase
    {
        get { return _selectedPhase; }
        set
        {
            _selectedPhase = value;
            this.NotifyPropertyChanged("SelectedPhase");
        }
    }

    public Contexte()
    {
        ListeDesAffaires = new ObservableCollection<Affaire>
        {
            new Affaire("Affaire1"),
            new Affaire("Affaire2")
        };
    }
}

public class Affaire : BaseViewModel
{
    private string nom;
    public string Nom
    {
        get { return this.nom; }
        set
        {
            this.nom = value;
            this.NotifyPropertyChanged("Nom");
        }
    }

    public ObservableCollection<Phase> ListPhases { get; set; }

    public Affaire(string n)
    {
        nom = n;
        ListPhases = new ObservableCollection<Phase>
        {
            new Phase { NomPhase = nom + "_Phase1" },
            new Phase { NomPhase = nom + "_Phase2" }
        };
    }
}

public class Phase : BaseViewModel
{
    private string nomPhase;
    public string NomPhase
    {
        get { return this.nomPhase; }
        set
        {
            this.nomPhase = value;
            this.NotifyPropertyChanged("NomPhase");
        }
    }

    public ObservableCollection<Assemblage> ListAssemblages { get; set; }
}

public class Assemblage : BaseViewModel
{
    private string nom;
    public string Nom
    {
        get { return this.nom; }
        set
        {
            this.nom = value;
            this.NotifyPropertyChanged("Nom");
        }
    }

}

}

a MainWindow.xaml:

<Window x:Class="WpfApp2.MainWindow"
        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:WpfApp2"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:Contexte x:Name="Contexte" d:IsDataSource="True" />
    </Window.DataContext>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="1*"/>
            <ColumnDefinition Width="1*"/>
            <ColumnDefinition Width="1*"/>
        </Grid.ColumnDefinitions>
        <ListBox ItemsSource="{Binding ListeDesAffaires}" DisplayMemberPath="Nom" SelectedItem="{Binding SelectedAffaire}"/>
        <ListBox Grid.Column="1" ItemsSource="{Binding SelectedAffaire.ListPhases}" DisplayMemberPath="NomPhase" />
        <Button Grid.Column="2" VerticalAlignment="Top" Click="FillClick">Fill</Button>
        <ListBox Grid.Column="2" ItemsSource="{Binding SelectedPhase.ListAssemblages}" DisplayMemberPath="Nom" Margin="0,20,0,0"/>
    </Grid>
</Window>

And some code from your question (MainWindow.xaml.cs):

using System.Collections.ObjectModel;
using System.Windows;

namespace WpfApp2
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void FillClick(object sender, RoutedEventArgs e)
        {
            Phase ph = new Phase();
            ph.NomPhase = "SomeId";
            ph.ListAssemblages = new ObservableCollection<Assemblage>()
            {
                new Assemblage { Nom =  "Assemblage1" },
                new Assemblage { Nom =  "Assemblage2" }
            };
            Contexte.SelectedPhase = ph;
        }
    }
}

And here is the result:

This is basic sample that you can extend. It handles all field modification and Add/Remove objects and displays on screen. There is no additional code in MainWindow.xaml.cs. Please ask questions, if any.