Binding to a multiselect Combobox

Question

I have a ListBox that pulls in "Programs" and can be multi selected with a checkbox indicating if it's selected or not. I'm wondering what's my next step, I have create the IsChecked binding but don't know how to associate it with the value and save the values to a database.

xaml side:

<ComboBox Grid.Row="1" ItemsSource="{Binding VisPrograms}" >
    <ComboBox.ItemTemplate>
         <DataTemplate>
              <CheckBox Content="{Binding Value}" 
                  IsChecked="{Binding Path=ProgramsIsSelected, Mode=TwoWay}"                                                 Tag="{RelativeSource FindAncestor, AncestorType={x:Type ComboBox}}">
              </CheckBox>
         </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

MVVM side:

private bool? programsIsSelected;
public bool? ProgramIsSelected
{
    get { return programsIsSelected; }
    set
    {
        programsIsSelected = value;
        OnPropertyChanged("ProgramIsSelected");
    }
}

What I want to accomplish (to clerify)

BindableCollection<Program> SelectedPrograms = new BindableCollection<Programs>

using (var ctx = DB.GET())
{
    foreach (Program _program in SelectedPrograms)
    {
        Program NewProgram = new Program();
        NewProgram.Person_Id = PersonId;
        NewProgram.Value = _program.value;
        ctx.Program.Add(NewProgram); 
    }
}

The code just above is what I want to do, But the part I have issues with is Populating SelectedPrograms or Depopulating selected programs.

Answer 1

Your last paragraph is quite unclear, nowhere on your question there is a Populating or Depopulating objects/properties.

Please clarify your question so we can better help you in addressing your current problem.

In the mean time here is some code that will:

• present each item with a checkbox that the user can check
• update each item according user selection

XAML:

<Window x:Class="WpfApplication7.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:wpfApplication7="clr-namespace:WpfApplication7"
        Title="MainWindow"
        Width="525"
        Height="350">
    <Grid>
        <ComboBox x:Name="CheckBox1"
                  Width="100"
                  HorizontalAlignment="Left"
                  VerticalAlignment="Top"
                  ItemsSource="{Binding}">
            <ComboBox.ItemTemplate>
                <DataTemplate DataType="wpfApplication7:MyItem">
                    <StackPanel Orientation="Horizontal">
                        <CheckBox IsChecked="{Binding IsChecked}" />
                        <TextBlock Text="{Binding Name}" />
                    </StackPanel>
                </DataTemplate>
            </ComboBox.ItemTemplate>
        </ComboBox>
    </Grid>
</Window>

Code behind:

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;

namespace WpfApplication7
{
    /// <summary>
    ///     Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            var collection = new MyItemCollection();
            collection.Add(new MyItem {Name = "item1", IsChecked = true});
            collection.Add(new MyItem {Name = "item2", IsChecked = false});

            CheckBox1.DataContext = collection;
        }
    }

    internal class MyItem : INotifyPropertyChanged
    {
        private bool _isChecked;
        private string _name;

        public string Name
        {
            get { return _name; }
            set
            {
                _name = value;
                OnPropertyChanged();
            }
        }

        public bool IsChecked
        {
            get { return _isChecked; }
            set
            {
                _isChecked = value;
                OnPropertyChanged();
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    internal class MyItemCollection : ObservableCollection<MyItem>
    {
    }
}