ContextMenuの中身をMVVMで動的に作成する

2020-06-07

MainView.xaml

<Window x:Class="WpfApp15.View.MainView"
        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:i="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:l="http://schemas.livet-mvvm.net/2011/wpf"
        xmlns:local="clr-namespace:WpfApp15.View"
        xmlns:vm="clr-namespace:WpfApp15.ViewModel"
        mc:Ignorable="d"
        Title="MainView" Height="450" Width="800">

    <Window.DataContext>
        <vm:MainViewModel/>
    </Window.DataContext>

    <i:Interaction.Triggers>
        <i:EventTrigger EventName ="Loaded">
            <l:LivetCallMethodAction MethodTarget="{Binding}" MethodName="OnLoaded" />
        </i:EventTrigger>
    </i:Interaction.Triggers>

    <Grid>
        <Button>
            <Button.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="MenuParent" ItemsSource="{Binding ArrayMenu1}">
                        <MenuItem.ItemContainerStyle>
                            <Style TargetType="MenuItem">
                                <Setter Property="Header" Value="{Binding DisplayName}"/>
                                <Setter Property="IsChecked" Value="{Binding Checked}"/>
                                <Setter Property="Command" Value="{Binding}"/>
                            </Style>
                        </MenuItem.ItemContainerStyle>
                    </MenuItem>
                </ContextMenu>
            </Button.ContextMenu>
        </Button>
    </Grid>
</Window>

MainViewModel.cs

using System;
using System.Collections.Generic;
using System.Windows;

namespace WpfApp15.ViewModel
{
    public class MainViewModel : Livet.ViewModel
    {
        /// <summary>
        /// コンテキストメニュー
        /// </summary>
        private List<ContextMenuClass> _ArrayMenu1 = new List<ContextMenuClass>();
        public List<ContextMenuClass> ArrayMenu1
        {
            get
            {
                return _ArrayMenu1;
            }
            set
            {
                _ArrayMenu1 = value;
                RaisePropertyChanged();
            }
        }

        /// <summary>
        /// 起動時処理
        /// </summary>
        public void OnLoaded()
        {
            for(int intCount = 0; intCount < 5; intCount++)
            {
                ContextMenuClass contextMenu = new ContextMenuClass("Menu" + intCount, intCount == 0 ? true : false);
                contextMenu.ExecuteEventHandler += (object sender, EventArgs e)=>
                {
                    foreach(ContextMenuClass Menu in ArrayMenu1)
                    {
                        Menu.Checked = Menu == sender ? true : false;
                    }

                    MessageBox.Show((sender as ContextMenuClass).DisplayName + " Selected");
                };
                ArrayMenu1.Add(contextMenu);
            }
        }
    }
}

ContextMenuClass.cs

using System;
using System.Windows.Input;

namespace WpfApp15.ViewModel
{
    /// <summary>
    /// コンテキストメニュークラス
    /// </summary>
    public class ContextMenuClass : Livet.ViewModel, ICommand
    {
        public ContextMenuClass(string strDisplayName, bool bolChecked)
        {
            this.DisplayName = strDisplayName;
            this.Checked = bolChecked;
        }

        private string _DisplayName = "";
        public string DisplayName
        {
            get
            {
                return _DisplayName;
            }
            set
            {
                _DisplayName = value;
                RaisePropertyChanged();
            }
        }

        private bool _Checked = false;
        public bool Checked
        {
            get
            {
                return _Checked;
            }
            set
            {
                _Checked = value;
                RaisePropertyChanged();
            }
        }

        public event EventHandler CanExecuteChanged;

        public bool CanExecute(object parameter)
        {
            return true;
        }

        // 選択時イベントハンドラ
        public event EventHandler ExecuteEventHandler;

        public void Execute(object parameter)
        {
            if (ExecuteEventHandler != null)
                ExecuteEventHandler(this, EventArgs.Empty);
        }
    }
}