WPF_Practice/PacticeSolution/DependencyPropertySample2/MainWindow.xaml.cs

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 DependencyPropertySample2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        // dependency property
        public static readonly DependencyProperty MyProperty = DependencyProperty.Register
            ("MyColor", typeof(string), typeof(MainWindow), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnMyPropertyChanged)));

        public MainWindow()
        {
            InitializeComponent();
        }

        public string MyColor
        {
            get { return (string)GetValue(MyProperty); }
            set { SetValue(MyProperty, value); }
        }

        private static void OnMyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            MainWindow win = d as MainWindow;
            if (win == null)
                return;

            SolidColorBrush brush = new BrushConverter().ConvertFromString(e.NewValue.ToString()) as SolidColorBrush;
            if (brush == null)
                return;

            win.Background = brush;
            win.Title = (e.OldValue == null) ? "Previous: None" : $"Previous: {e.OldValue.ToString()}";
            win.tbMain.Text = e.NewValue.ToString();
        }

        private void ContextMenu_Click(object sender, RoutedEventArgs e)
        {
            string str = (e.Source as MenuItem).Header as string;
            if (string.IsNullOrEmpty(str))
                return;

            this.MyColor = str;
        }
    }
}