SAS是否有像Java这样的并发框架(Does SAS have a concurrency framework like Java)

 这是问题： answer = MyQuestion(question).Result; 。 
 
 在Task上使用Result意味着“得到结果，但如果它还不可用，请等待 - 即阻止线程等待结果”。 
 
 由于MyQuestion等待来自TaskCompletionSource的Task应该完成QuestionManager或其他UI代码，而QuestionManager （通过Result ）正在等待MyQuestion完成，所以你有一个死锁！ QuestionManager阻止了UI线程，因此tcs无法通过下一行或任何其他运行的UI代码接收结果。 
 
 将Result更改为await它，这将消失。 我不确定其余的逻辑是否会保持在一起，但这就是为什么在运行您发布的代码时UI会锁定的答案。 
 
 
 至于如何解决这个问题：这些都不需要任何异步等待。 使用异步会掩盖您实际想要编写的代码，并且您正在使用async void方法，这几乎总是一个坏主意 。 
 
 我要做的是有一个具有问题和答案属性的类，保留所有剩余问题和答案的列表，并且每当提交新答案时始终对该列表中的第一项起作用，以查看答案是否为正确 - 您将知道是否显示“错误答案”并让他们再次尝试或是否进入下一个问题。 
 
 例如： 
 
class QuestionAndAnswer {
    public string Question { get; set; } 
    public string Answer { get; set; }
}

private List<QuestionAndAnswer> _currentQuestions; // create this list when loading everything

private int _currentQuestionIndex = 0; // points to which element/index in the list contains the question shown on screen

// call this once after you have loaded _currentQuestions with your data
public void ShowCurrentQuestion() { 
    var currQuestion = _currentQuestion[_currentQuestionIndex];
    computerQuestionLabel.Text = currQuestion.Question;
    answerTextBox.Text = "";
}

// call this from whichever event handler means that the user has
// submitted an answer - an Answer button's Click event, maybe
// answerTextBox's KeyPress event or something else.
public void CheckForAnswer() {
    var currentAnswer = answerTextBox.Text;
    var currQuestion = _currentQuestion[_currentQuestionIndex];
    if (currQuestion.Answer == currentAnswer) { // correct
        var nextQuestionIndex = _currentQuestionIndex + 1;
        if (nextQuestionIndex == _currentQuestion.Count) { 
            // all questions answered! do the appropriate thing
        } else {
            // still questions left, show the next one
            _currentQuestionIndex = nextQuestionIndex;
            ShowCurrentQuestion();
        }
    } else {
        // wrong answer; the question that needs to be shown is 
        // already shown, you can handle "stop" or other things here
    }
}
 
 这里有一个自然事件，意思是“有人刚刚提交了一个新答案”，您可以将其用作漏斗点。 没有必要编写等待新答案的代码。 通过编写使事件响应用户事件而发生的代码，您已经实际上异步处理（做你的事情，等待用户做某事，做更多事情），这只是你没有使用async / await / Task s或显式编写异步代码来完成它。 

This is the issue: answer = MyQuestion(question).Result;.
 
Using Result on a Task means "get me the result, but if it's not yet available, wait - ie block the thread waiting for the result of this".
 
Since MyQuestion waits for the Task from a TaskCompletionSource that QuestionManager or other UI code is supposed to complete, and QuestionManager (through Result) is waiting for MyQuestion to finish, you have a deadlock! QuestionManager is blocking the UI thread, so tcs can't receive a result either through the next line or through any other UI code running.
 
Change Result to awaiting it, and this will go away. I am not certain that the rest of the logic will hold together, but this is the answer to why the UI locks up when you run the code you posted.
 
 
As for how to solve this: none of this actually requires any asynchronous waiting. Using asynchrony obscures the code you actually want to write, and you're using async void methods which is nearly always a bad idea.
 
What I would do is have a class with properties for a question and an answer, keep a list of all remaining questions-and-answers and always work against the first item in that list whenever a new answer is submitted to see if the answer is correct - you'll know whether to show "wrong answer" and have them try again or whether to advance to the next question.
 
For example:
 
class QuestionAndAnswer {
    public string Question { get; set; } 
    public string Answer { get; set; }
}

private List<QuestionAndAnswer> _currentQuestions; // create this list when loading everything

private int _currentQuestionIndex = 0; // points to which element/index in the list contains the question shown on screen

// call this once after you have loaded _currentQuestions with your data
public void ShowCurrentQuestion() { 
    var currQuestion = _currentQuestion[_currentQuestionIndex];
    computerQuestionLabel.Text = currQuestion.Question;
    answerTextBox.Text = "";
}

// call this from whichever event handler means that the user has
// submitted an answer - an Answer button's Click event, maybe
// answerTextBox's KeyPress event or something else.
public void CheckForAnswer() {
    var currentAnswer = answerTextBox.Text;
    var currQuestion = _currentQuestion[_currentQuestionIndex];
    if (currQuestion.Answer == currentAnswer) { // correct
        var nextQuestionIndex = _currentQuestionIndex + 1;
        if (nextQuestionIndex == _currentQuestion.Count) { 
            // all questions answered! do the appropriate thing
        } else {
            // still questions left, show the next one
            _currentQuestionIndex = nextQuestionIndex;
            ShowCurrentQuestion();
        }
    } else {
        // wrong answer; the question that needs to be shown is 
        // already shown, you can handle "stop" or other things here
    }
}
 
There's a natural event here meaning "someone just submitted a new answer", and you can use that as a funnel point. There's no need to write code that waits for new answers. By writing code that makes things happen in response to user events, you are already in effect doing things asynchronously (do your stuff, wait for the user to do something, do even more stuff), it's just that you're not using async/await/Tasks or writing explicitly asynchronous code to do it.