实现Icommand接口

public class RelayCommand : ICommand
    {
        private Action<object> _execute;

        private Predicate<object> _canExecute;

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

        public RelayCommand(Action<object> execute) : this(execute, null)
        {
        }

        public RelayCommand(Action<object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
            {
                throw new ArgumentNullException("execute");
            }
            this._execute = execute;
            this._canExecute = canExecute;
        }

        [DebuggerStepThrough]
        public bool CanExecute(object parameter)
        {
            return this._canExecute == null || this._canExecute(parameter);
        }

        public void Execute(object parameter)
        {
            this._execute(parameter);
        }
    }