xml 【执笔中】【WPF】【MVVM】动的なコントロールに対して，动的なコンテキストメニューを构成する。

Posted 2021-05-17

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;

namespace ContextMenuTest.ViewModel
{
	public class MyViewModel : INotifyPropertyChanged
	{
		private ObservableCollection<BorderItem> borders;
		public ObservableCollection<BorderItem> Borders
		{
			get { return this.borders; }
			set
			{
				if (this.borders != value) {
					this.borders = value;
					NotifyPropertyChaned("Borders");
				}
			}
		}

		#region INotifyPropertyChanged メンバー

		public event PropertyChangedEventHandler PropertyChanged;
		private void NotifyPropertyChaned(string arg)
		{
			if (PropertyChanged != null) {
				PropertyChanged(this, new PropertyChangedEventArgs(arg));
			}
		}
		#endregion

		public MyViewModel()
		{
			var menu1 = new[]
			{
				new ContextMenuItem("Add", null, Visibility.Visible),
				new ContextMenuItem("Edit", null, Visibility.Visible),
				new ContextMenuItem("Copy", null, Visibility.Collapsed),
				new ContextMenuItem("Delete", null, Visibility.Visible),
			};

			var menu2 = new[]
			{
				new ContextMenuItem("Add", null, Visibility.Visible),
			};

			var menu3 = new[]
			{
				new ContextMenuItem("Copy", null, Visibility.Collapsed),
				new ContextMenuItem("Delete", null, Visibility.Visible),
			};

			this.Borders = new ObservableCollection<BorderItem>() {
				new BorderItem(new SolidColorBrush(Colors.Red), menu1),
				new BorderItem(new SolidColorBrush(Colors.Blue), menu2),
				new BorderItem(new SolidColorBrush(Colors.Purple), menu3),
			};
		}
	}

	public class BorderItem : INotifyPropertyChanged
	{
		private Brush backgroundColor;
		public Brush BackgroundColor
		{
			get { return this.backgroundColor; }
			set
			{
				if (this.backgroundColor != value) {
					this.backgroundColor = value;
					NotifyPropertyChaned("BackgroundColor");
				}
			}
		}

		private ObservableCollection<ContextMenuItem> menus;
		public ObservableCollection<ContextMenuItem> Menus
		{
			get { return this.menus; }
			set
			{
				if (this.menus != value) {
					this.menus = value;
					NotifyPropertyChaned("Menus");
				}
			}
		}

		#region INotifyPropertyChanged メンバー

		public event PropertyChangedEventHandler PropertyChanged;
		private void NotifyPropertyChaned(string arg)
		{
			if (PropertyChanged != null) {
				PropertyChanged(this, new PropertyChangedEventArgs(arg));
			}
		}
		#endregion

		public BorderItem(Brush b, ContextMenuItem[] m)
		{
			this.BackgroundColor = b;
			this.Menus = new ObservableCollection<ContextMenuItem>(m);
		}
	}


	public class ContextMenuItem : INotifyPropertyChanged
	{
		private string title;
		public string Title
		{
			get { return this.title; }
			set
			{
				if (this.title != value) {
					this.title = value;
					NotifyPropertyChaned("Title");
				}
			}
		}

		private ICommand command;
		public ICommand Command
		{
			get { return this.command; }
			set
			{
				if (this.command != value) {
					this.command = value;
					NotifyPropertyChaned("Title");
				}
			}
		}

		private Visibility visibility;
		public Visibility Visibility
		{
			get { return this.visibility; }
			set
			{
				if (this.visibility != value) {
					this.visibility = value;
					NotifyPropertyChaned("Visibility");
				}
			}
		}

		#region INotifyPropertyChanged メンバー

		public event PropertyChangedEventHandler PropertyChanged;
		private void NotifyPropertyChaned(string arg)
		{
			if (PropertyChanged != null) {
				PropertyChanged(this, new PropertyChangedEventArgs(arg));
			}
		}

		#endregion

		public ContextMenuItem(string t, ICommand c, Visibility v)
		{
			this.Title = t;
			this.Command = c;
			this.Visibility = v;
		}
	}
}

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;
using ContextMenuTest.ViewModel;

namespace ContextMenuTest
{
	/// <summary>
	/// MainWindow.xaml の相互作用ロジック
	/// </summary>
	public partial class MainWindow : Window
	{

		public MainWindow()
		{
			InitializeComponent();
			var vm = new MyViewModel();
			this.DataContext = vm;
		}
	}
}

<Window x:Class="ContextMenuTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
	<Grid>
		<Grid.ColumnDefinitions>
			<ColumnDefinition/>
			<ColumnDefinition/>
		</Grid.ColumnDefinitions>
		<Border Width="100" Height="100" Background="Aqua">
			<Border.ContextMenu>
				<ContextMenu>
					<MenuItem Header="Add"/>
					<MenuItem Header="Edit"/>
					<MenuItem Header="Delete"/>
				</ContextMenu>
			</Border.ContextMenu>
		</Border>
		<ItemsControl Grid.Column="1" ItemsSource="{Binding Borders}">
			<ItemsControl.ItemTemplate>
				<DataTemplate>
					<Border Width="30" Height="30" Background="{Binding BackgroundColor}">
						<Border.ContextMenu>
							<ContextMenu ItemsSource="{Binding Menus}">
								<ContextMenu.ItemContainerStyle>
									<Style TargetType="{x:Type MenuItem}">
										<Setter Property="Header" Value="{Binding Title}" />
										<Setter Property="Command" Value="{Binding Command}" />
										<Setter Property="Visibility" Value="{Binding Visibility}"/>
									</Style>
								</ContextMenu.ItemContainerStyle>
							</ContextMenu>
						</Border.ContextMenu>
					</Border>
				</DataTemplate>
			</ItemsControl.ItemTemplate>
		</ItemsControl>
	</Grid>
</Window>