WPF Button Command and CommandParamet completed via C# no xaml at all

  private void ButtonCommandBinding()
  {
      Button btn = new Button();
      btn.Width = 500;
      btn.Height = 300;
      btn.Content = "Show Info";
      btn.Background = new SolidColorBrush(Colors.Blue); 
      btn.Command = ShowCmd;
      btn.CommandParameter = this;
      this.Content = btn;
  }

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 WpfApp284
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.WindowState = WindowState.Maximized;
            InitCmds();
            ButtonCommandBinding();
        }

        private void InitCmds()
        {
            ShowCmd = new DelCmd(ShowCmdExecuted);
        }

        private void ShowCmdExecuted(object obj)
        {
            var win = obj as Window;
            if(win!=null)
            {
                MessageBox.Show($"Now is {DateTime.Now.ToString("yyyyMMddHHmmffff")},Width:{win.ActualWidth},Height:{win.ActualHeight}");
            }
        }

        private void ButtonCommandBinding()
        {
            Button btn = new Button();
            btn.Width = 500;
            btn.Height = 300;
            btn.Content = "Show Info";
            btn.Background = new SolidColorBrush(Colors.Blue); 
            btn.Command = ShowCmd;
            btn.CommandParameter = this;
            this.Content = btn;
        }

        public DelCmd ShowCmd { get; set; }
    }

    public class DelCmd : ICommand
    {
        public event EventHandler CanExecuteChanged
        {
            add
            {
                CommandManager.RequerySuggested += value;
            }
            remove
            {
                CommandManager.RequerySuggested -= value;
            }
        }

        private Action<object> execute;
        private Predicate<object> canExecute;

        public DelCmd(Action<object> executeValue,Predicate<object> canExecuteValue)
        {
            execute= executeValue;
            canExecute= canExecuteValue;
        }
        public DelCmd(Action<object> executeValue):this(executeValue,null)
        {
            
        }

        public bool CanExecute(object parameter)
        {
            if(canExecute==null)
            {
                return true;
            }
            return canExecute(parameter);
        }

        public void Execute(object parameter)
        {
            execute(parameter);
        }
    }
}