WPF_Practice/PacticeSolution/ListBoxLinqBindingSample/MainWindow.xaml.cs

using ListBoxLinqBindingSample.Model;
using ListBoxLinqBindingSample.SubWindow;
using ListBoxLinqBindingSample.ViewModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace ListBoxLinqBindingSample
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private static Duties _duties = new Duties();

        public delegate void RefreshList(DutyType dutyType);
        public event RefreshList RefreshListEvent;

        public MainWindow()
        {
            InitializeComponent();
        }

        internal static Duties Duties
        {
            get { return _duties; }
            set { _duties = value; }
        }

        private void RefreshListBox(DutyType dutyType)
        {
            lstType.SelectedItem = null;
            lstType.SelectedIndex = dutyType == DutyType.Inside ? 0 : 1;
        }

        private void btnAdd_Click(object sender, RoutedEventArgs e)
        {
            SubWindow.SubWindow subWindow = new SubWindow.SubWindow();

            this.RefreshListEvent += new RefreshList(RefreshListBox);
            subWindow.UpdateActor = this.RefreshListEvent;
            subWindow.Show();
        }

        private void lstType_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListBox lb = sender as ListBox;
            if (lb == null)
                return;

            if (lb.SelectedItem == null)
                return;

            ListBoxItem item = lb.SelectedItem as ListBoxItem;
            string dutyType = item.Content.ToString();

            this.DataContext = from duty in _duties
                               where duty.DutyType.ToString() == dutyType
                               select duty;
        }

        private void lstMain_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListBox lb = sender as ListBox;
            if (lb == null)
                return;

            if (lb.SelectedItem == null)
                return;

            Duty duty = lb.SelectedItem as Duty;
            if (duty == null) 
                return;

            MessageBox.Show($"{duty.Name} :: {duty.DutyType}", "Selected duty");
        }
    }
}