WPF_Practice/PacticeSolution/CommandSample/Commands/MessageCommand.cs

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

namespace CommandSample.Commands
{
    internal class MessageCommand : ICommand
    {
        private Action<string> _execute;
        private Predicate<string> _canExecute;

        public event EventHandler? CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

        public MessageCommand(Action<string> execute, Predicate<string> canExecute)
        {
            _execute = execute;
            _canExecute = canExecute;
        }

        public bool CanExecute(object? parameter)
        {
            bool result = _canExecute.Invoke(parameter as string);
            return result;
        }

        public void Execute(object? parameter)
        {
            if (_execute == null)
                return;

            _execute.Invoke(parameter as string);
        }
    }
}