Multiple ways to handle Checked/Unchecked event in wpf using MVVM

In this post i am trying to explain multiple way to handle Checked/Unchecked event in wpf using MVVM

First let's create a view which contains multiple CheckBox. 

All CheckBox will handle the Checked/Unchecked event differently. 

CheckBoxEx.xaml

<Window x:Class="PrismApp.Views.CheckBoxEx"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"
             prism:ViewModelLocator.AutoWireViewModel="True">
    <StackPanel >
        <CheckBox Content="Bind Command by passing CheckBox as CommandParameter but set command parameter type is object" HorizontalAlignment="Left" VerticalAlignment="Center"  Name="chkObj"
                  Command="{Binding CheckedChangedCommand}" CommandParameter="{Binding ElementName=chkObj}"/>
        <CheckBox Content="Bind Command by passing CheckBox as CommandParameter" HorizontalAlignment="Left" VerticalAlignment="Center"  Name="chk"
                  Command="{Binding CheckedByCheckBoxCommand}" CommandParameter="{Binding ElementName=chk}"/>
        <CheckBox Content="Bind Command by passing CheckBox IsChecked property as CommandParameter" HorizontalAlignment="Left" VerticalAlignment="Center"  Name="chkbx"
                  Command="{Binding CheckedByIsCheckedPropertyCommand}" CommandParameter="{Binding ElementName=chkbx,Path=IsChecked}"/>
        <CheckBox Content="Bind Command by passing DataContext as CommandParameter" HorizontalAlignment="Left" VerticalAlignment="Center"
                  Command="{Binding CheckedByDataContextCommand}" IsChecked="{Binding IsVmChecked}" CommandParameter="{Binding}"/>
        <CheckBox Content="By Binding IsChecked property of CheckBox with VM property" HorizontalAlignment="Left" VerticalAlignment="Center"
                 IsChecked="{Binding IsChecked}" />
    </StackPanel>
</Window>

CheckBoxEx.xaml.cs

    public partial class CheckBoxEx : Window
    {
        public CheckBoxEx()
        {
            InitializeComponent();
        }







    }


CheckBoxExViewModel.cs

using Prism.Commands;
using Prism.Mvvm;
using System.Windows.Controls;
using System.Windows;

    public class CheckBoxExViewModel : BindableBase
    {
        public CheckBoxExViewModel()
        {

        }

        #region 5 ways to handle the Checked/UnChecked of CheckBox using Command

        #region Way 1: When command parameter type is object need to cast
        private DelegateCommand<object> _checkedChangedCommand;
        public DelegateCommand<object> CheckedChangedCommand => (_checkedChangedCommand = new DelegateCommand<object>(CheckChanged));

        private void CheckChanged(object obj)
        {
            var chekbox = obj as CheckBox;
            MessageBox.Show($"Checkbox is checked (Bind Command by passing CheckBox as CommandParameter but set command parameter type is object) :{chekbox.IsChecked}");

        }
        #endregion

        #region Way 2: When command parameter type is CheckBox no need to cast






        private DelegateCommand<CheckBox> _checkedByCheckBoxCommand;
        public DelegateCommand<CheckBox> CheckedByCheckBoxCommand => (_checkedByCheckBoxCommand = new DelegateCommand<CheckBox>(CheckedByCheckBoxChanged));

        private void CheckedByCheckBoxChanged(CheckBox chekbox)
        {
            MessageBox.Show($"Checkbox is checked (Bind Command by passing CheckBox as CommandParameter) :{chekbox.IsChecked}");

        }
        #endregion

        #region Way 3:When command parameter type is CheckBox IsChecked property type
        private DelegateCommand<bool?> _checkedByIsCheckedPropertyCommand;
        public DelegateCommand<bool?> CheckedByIsCheckedPropertyCommand => (_checkedByIsCheckedPropertyCommand = new DelegateCommand<bool?>(CheckedByIsCheckedPropertyChange));
        private void CheckedByIsCheckedPropertyChange(bool? isChecked)
        {
            MessageBox.Show($"Checkbox is checked (Bind Command by passing CheckBox IsChecked property as CommandParameter):{isChecked}");

        }
        #endregion








        #region Way 4:When command parameter type is DataContext
        private bool _isVmChecked;

        public bool IsVmChecked
        {
            get { return _isVmChecked; }
            set
            {
                SetProperty(ref _isVmChecked, value);
            }
        }
        private DelegateCommand<CheckBoxExViewModel> _checkedByDataContextCommand;
        public DelegateCommand<CheckBoxExViewModel> CheckedByDataContextCommand => (_checkedByDataContextCommand = new DelegateCommand<CheckBoxExViewModel>(CheckedByDataContextChange));
        private void CheckedByDataContextChange(CheckBoxExViewModel datacontext)
        {
            MessageBox.Show($"Checkbox is checked (Bind Command by passing DataContext as CommandParameter):{datacontext.IsChecked}");

        }
        #endregion

        #region Way 5: By Binding IsChecked property of CheckBox
        private bool _isChecked;

        public bool IsChecked
        {
            get { return _isChecked; }
            set
            {
                SetProperty(ref _isChecked, value);
                MessageBox.Show($"Checkbox is checked (By Binding IsChecked property of CheckBox):{_isChecked}");
            }
        }
        #endregion

        #endregion
    }

Note: Way 1 and Way 2 are not recommended to use because we should not use any Views components in ViewModel.