/// <summary>
/// Redo操作が可能か調べます。
/// </summary>
private static void CanExecuteRedo(object sender, CanExecuteRelayEventArgs e)
{
var element = e.Parameter as GLShogiElement;
if (element == null)
{
throw new ArgumentNullException("element");
}
if (element.Board == null)
{
throw new InvalidOperationException(
"element.Boardがnullです。");
}
e.CanExecute = element.Board.CanRedo;
}
/// <summary>
/// コマンドの実行可能状態を調べます。
/// </summary>
public bool CanExecute()
{
if (this.canExecute == null)
{
return true;
}
var e = new CanExecuteRelayEventArgs(this);
this.canExecute(this, e);
return e.CanExecute;
}