我正在使用一个RelayCommand来实现执行和可执行操作。当没有canExecute部分时,RelayCommand可以工作,但是当我添加canExecute部分时,命令会锁定按钮。只要CanExecute部分为true,RelayCommand就会检查按钮是否可以执行。一旦canExecute部分变为false,即使应该能够执行,按钮也无法再次单击。我如何确保每次单击按钮时都控制它是否可以执行,而不是永久锁定它,一旦它不能执行?
RedoCommand = new RelayCommand(undoRedoController.Redo,undoRedoController.CanRedo);
public bool CanRedo()
{
redoStack.Count();
redoStack.Any();
return redoStack.Any();
}
public void Redo()
{
if (redoStack.Count() <= 0) throw new InvalidOperationException();
IUndoRedoCommand command = redoStack.Pop();
undoStack.Push(command);
command.Execute();
}
public class UndoRedoController
{
private static UndoRedoController controller = new UndoRedoController();
private readonly Stack<IUndoRedoCommand> undoStack = new Stack<IUndoRedoCommand>();
private readonly Stack<IUndoRedoCommand> redoStack = new Stack<IUndoRedoCommand>();
private UndoRedoController() { }
public static UndoRedoController GetInstance() { return controller; }