Ejemplo n.º 1
0
        private ChoicePromptHandler CreateChoicePromptHandler()
        {
            if (this.activePromptHandler != null)
            {
                Logger.LogError(
                    "Prompt handler requested while another prompt is already active.");
            }

            ChoicePromptHandler choicePromptHandler = this.OnCreateChoicePromptHandler();

            this.activePromptHandler = choicePromptHandler;
            this.activePromptHandler.PromptCancelled += activePromptHandler_PromptCancelled;

            return(choicePromptHandler);
        }
        /// <summary>
        /// Prompts the user to make a choice using the provided details.
        /// </summary>
        /// <param name="promptCaption">
        /// The caption string which will be displayed to the user.
        /// </param>
        /// <param name="promptMessage">
        /// The descriptive message which will be displayed to the user.
        /// </param>
        /// <param name="choices">
        /// The list of choices from which the user will select.
        /// </param>
        /// <param name="defaultChoice">
        /// The default choice to highlight for the user.
        /// </param>
        /// <param name="cancellationToken">
        /// A CancellationToken that can be used to cancel the prompt.
        /// </param>
        /// <returns>
        /// A Task instance that can be monitored for completion to get
        /// the user's choice.
        /// </returns>
        public Task <int> PromptForChoiceAsync(
            string promptCaption,
            string promptMessage,
            ChoiceDetails[] choices,
            int defaultChoice,
            CancellationToken cancellationToken)
        {
            // TODO: Guard against multiple calls

            this.Caption = promptCaption;
            this.Message = promptMessage;
            this.Choices = choices;

            this.DefaultChoices =
                defaultChoice == -1
                ? Array.Empty <int>()
                : new int[] { defaultChoice };

            // Cancel the TaskCompletionSource if the caller cancels the task
            cancellationToken.Register(this.CancelPrompt, true);

            // Convert the int[] result to int
            return(this.WaitForTaskAsync(
                       this.StartPromptLoopAsync(this.promptCancellationTokenSource.Token)
                       .ContinueWith(
                           task =>
            {
                if (task.IsFaulted)
                {
                    throw task.Exception;
                }
                else if (task.IsCanceled)
                {
                    throw new TaskCanceledException(task);
                }

                return ChoicePromptHandler.GetSingleResult(task.GetAwaiter().GetResult());
            })));
        }