示例#1
-1
        public STextBox(Stream<string> setText, string initText, Cell<bool> enabled)
        {
            base.Text = initText;

            List<IListener> listeners = new List<IListener>();

            StreamSink<int> sDecrement = new StreamSink<int>();
            Cell<bool> allow = setText.Map(_ => 1).OrElse(sDecrement).Accum(0, (b, d) => b + d).Map(b => b == 0);

            StreamSink<string> sUserChanges = new StreamSink<string>();
            this.SUserChanges = sUserChanges;
            this.Text = sUserChanges.Gate(allow).OrElse(setText).Hold(initText);

            TextChangedEventHandler textChangedEventHandler = (sender, args) =>
            {
                string text = base.Text;
                this.Dispatcher.InvokeAsync(() => sUserChanges.Send(text));
            };

            this.TextChanged += textChangedEventHandler;

            // Set the initial value at the end of the transaction so it works with CellLoops.
            Transaction.Post(() => this.Dispatcher.InvokeIfNecessary(() => this.IsEnabled = enabled.Sample()));

            listeners.Add(setText.Listen(t =>
            {
                this.Dispatcher.InvokeAsync(() =>
                {
                    this.TextChanged -= textChangedEventHandler;
                    base.Text = t;
                    this.TextChanged += textChangedEventHandler;
                    sDecrement.Send(-1);
                });
            }));

            listeners.Add(Operational.Updates(enabled).Listen(e => this.Dispatcher.InvokeIfNecessary(() => this.IsEnabled = e)));

            this.disposeListeners = () =>
            {
                foreach (IListener l in listeners)
                {
                    using (l)
                    {
                    }
                }
            };
        }