CheckComboBox.SelectedItemsOverride Loses All Selections

[MaroisConsulting]

I have a CheckComboBox on a tab control. I populate the ItemsSource and SelectedItemsOverride and everything seems to work fine. Both lists are ObservableCollections.

If I navigate to another tab, as soon as the current tab loses foces the control removes each item from the SelectedItemsOverride list. The CollectionChanges event for the SelectedItemsOverride list is called once for each item as it's being removed.

There is no other code getting called in my View & ViewModel that I can see. There's nothing in the call stack exept "External Code"

[XceedBoucherS]

Hi, I cannot reproduce this issue in v3.8 and up. Here's the sample I used:

  <TabItem Header="Second">
    <TextBox Text="ABC" />
  </TabItem>
</TabControl>

`public partial class MainWindow : Window { public MainWindow() { InitializeComponent();

  this.DataContext = this;

  this.Players = new ObservableCollection<Player>()
  {
    new Player() { FirstName = "Carey", LastName = "Price" },
    new Player() { FirstName = "Max", LastName = "Domi" },
    new Player() { FirstName = "Shea", LastName = "Weber" },
    new Player() { FirstName = "Jonathan", LastName = "Drouin" },
    new Player() { FirstName = "Brendan", LastName = "Gallagher" },
  };

  this.SelectedPlayers = new ObservableCollection<Player>();
  this.SelectedPlayers.CollectionChanged += SelectedPlayers_CollectionChanged;
}

private void SelectedPlayers_CollectionChanged( object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e )
{
}

public ObservableCollection<Player> Players
{
  get;
  set;
}

public ObservableCollection<Player> SelectedPlayers
{
  get;
  set;
}

}

public class Player { public string FirstName { get; set; } public string LastName { get; set; } }`

[Leszy77]

When "SelectedPlayers" collection is a ReactiveUI.ReactiveList, it works ok in version 3.2.0. The bug exists in version 3.5.0 and the latest, 4.0.1.

I have no idea why this happens. Any clues would be appreciated.

[Alex-ok2005]

I have the same problem. Is there any solution?

If you switch TabControl several times, CheckComboBox loses its selection. But not completely. In accordance with the smallest number of items used in other CheckComboBox items.

ViewModel:

    public class ViewModel : INotifyPropertyChanged
    {
        private Client selectedClient;
        public Client SelectedClient
        {
            get { return selectedClient; }
            set
            {
                selectedClient = value;
                OnPropertyChanged("SelectedClient");
            }
        }
        public class Client : INotifyPropertyChanged
        {
            private string clientName;
            public string ClientName
            {
                get { return clientName; }
                set
                {
                    clientName = value;
                    OnPropertyChanged("ClientName");
                }
            }
            public ObservableCollection<string> OrderItems { get; set; }
            public ObservableCollection<string> SelectedOrderItems { get; set; }
            public Client(string newClient)
            {
                ClientName = newClient;
                OrderItems = new ObservableCollection<string>();
                SelectedOrderItems = new ObservableCollection<string>();
            }
            public event PropertyChangedEventHandler PropertyChanged;
            public void OnPropertyChanged([CallerMemberName]string prop = "")
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(prop));
            }
        }
        public ObservableCollection<Client> Clients { get; set; }
        public ViewModel()
        {
            Clients = new ObservableCollection<Client>();
            Client _client = new Client("Client No.1");
            _client.OrderItems.Add("Order No.1");
            _client.SelectedOrderItems.Add("Order No.1");
            Clients.Add(_client);

            _client = new Client("Client No.2");
            _client.OrderItems.Add("Order No.1");
            _client.OrderItems.Add("Order No.2");
            _client.SelectedOrderItems.Add("Order No.1");
            _client.SelectedOrderItems.Add("Order No.2");
            Clients.Add(_client);

            _client = new Client("Client No.3");
            _client.OrderItems.Add("Order No.1");
            _client.OrderItems.Add("Order No.2");
            _client.OrderItems.Add("Order No.3");
            _client.SelectedOrderItems.Add("Order No.1");
            _client.SelectedOrderItems.Add("Order No.2");
            _client.SelectedOrderItems.Add("Order No.3");
            Clients.Add(_client);

            SelectedClient = Clients.FirstOrDefault();
        }
        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged([CallerMemberName]string prop = "")
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(prop));
        }
    }

XAML:

<Window x:Class="TestCheckComboBox.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:TestCheckComboBox"
        xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
        mc:Ignorable="d"
        Title="MainWindow" Height="250" Width="400" WindowStartupLocation="CenterScreen">
    <Grid>
        <TabControl
            ItemsSource="{Binding Clients}"
            SelectedItem="{Binding SelectedClient, Mode=TwoWay}" Margin="10">
            <TabControl.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding ClientName}" />
                </DataTemplate>
            </TabControl.ItemTemplate>
            <TabControl.ContentTemplate>
                <DataTemplate>
                    <Grid>
                        <xctk:CheckComboBox 
                            VerticalAlignment="Top"
                            Height="25"
                            Width="200"
                            Margin="20,20,0,0"
                            ItemsSource="{Binding OrderItems, Mode=OneWay}"
                            Delimiter = "; "
                            SelectedItemsOverride="{Binding SelectedOrderItems, Mode=TwoWay}">
                        </xctk:CheckComboBox>
                    </Grid>
                </DataTemplate>
            </TabControl.ContentTemplate>
        </TabControl>
    </Grid>
</Window>

Full project code

[XceedBoucherS]

Hi, I was able to reproduce @Alex-ok2005 issue. This will be fixed in v4.1. In the meantime, go in file Xceed.Wpf.Toolkit/Primitives/Selector.cs: 1) In method OnItemsSourceChanged, add the check: if( this.SelectedItemsOverride == null ) just before calling this.RemoveUnavailableSelectedItems();

2) In method OnItemsChanged, add the check: if( this.ItemsSource == null ) justr before calling this.RemoveUnavailableSelectedItems();

[Alex-ok2005]

Thank's a lot, it worked