xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
          <i:Interaction.Triggers>
                    <i:EventTrigger EventName="SelectionChanged">
                        <i:InvokeCommandAction Command="{Binding DoubleClick}"/>
                    </i:EventTrigger>
          </i:Interaction.Triggers>


          ClickPrintPass = new RelayCommand(argv => PrintPass());

                  public RelayCommand(Action<object> action)
        {
            ExecuteDelegate = action;
        }
        public Predicate<object> CanExecuteDelegate { get; set; }
        public Action<object> ExecuteDelegate { get; set; }

        public bool CanExecute(object parameter)
        {
            if (CanExecuteDelegate != null)
            {
                return CanExecuteDelegate(parameter);
            }
            return true;
        }
        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }
        public void Execute(object parameter)
        {
            if (ExecuteDelegate != null)
            {
                ExecuteDelegate(parameter);
            }
        }
    }