SWIFT - 致命错误：在展开Optional值时意外发现nil

2 回答

• 0

  确保 newQuestion 数组不是 nil 并且索引10的值为非零值 .

  如果我在这里提到的内容已经完成，请随意使用此数组的内容更新您的问题 .

  Edit

  现在我可以看到更多代码了，这很明显：

  你说 newQuestion[9].integerValue 但你应该使用 newQuestion[5].integerValue . 您要查找的整数值位于索引5，而不是9 .

  回复于 2024-05-22T00:05:00+08:00
• 0

  我可能错了，但以下几行似乎是错误的：

  var newQuestion: AnyObject = arrayOfQuestions[currentQuestion]
  questionCorrectAnswer = newQuestion[9].integerValue
  

  你声明 newQuestion 是AnyObject类型，它是 not 一个数组类型，然后你在下一行中取消引用它就好像它是一个数组！这会触发致命错误！

  我建议您将 arrayOfQuestions 的声明更改为 var arrayOfQuestions : Array<Question>() 之类的内容，并考虑使用for循环来实现 nextQuestion() 的其他一些功能 . 也许类似于以下内容：

  // Build the array of Questions
  var arrayOfQuestions = Array<Question>()
  
  arrayOfQuestions.append(Question(question: "Why?", answerOne: "Because", answerTwo: "Whatever", correctAnswer: 2))
  arrayOfQuestions.append(Question(question: "How?", answerOne: "Like this!", answerTwo: "Don't know", correctAnswer: 1))
  // ... repeat until you have all questions you want
  
  
  func nextQuestion() {
      currentQuestionNumber += 1
      let numberOfQuestions = countElements(arrayOfQuestions)
  
      // To look at the current questions specifics either do this ...
      let currQuestion: arrayOfQuestions[currentQuestionCounter]         
      let question = currQuestion.question
      let correctAnswer = currQuestion.correctAnswer
  
      // ... or something like
      let question = arrayOfQuestions[currenQuestionNumber].question
      let correctAnswer = arrayOfQuestions[currentQuestionNumber].correctAnswer
  
      for (var i = 0; i < countElements(arrayOfQuestions); i++) {
          if i <= currentQuestionNumber {
              answer[i].hidden = false
              answer[i].setTitle(arrayOfQuestions[i].question, forState: UIControlState.Normal
          } else {
              answer[i].hidden = true;
          }   
       }
  
   }
  

  回复于 2024-05-22T00:05:00+08:00