Xcode 8.3.3 中的 iOS Swift Researchkit 谓词问题

Posted 2023-02-16

【中文标题】Xcode 8.3.3 中的 iOS Swift Researchkit 谓词问题

【英文标题】：iOS Swift Researchkit Predicate issue in Xcode 8.3.3

【发布时间】：2018-03-19 23:52:05

【问题描述】：

我正在工作基于 Researchkit 的应用程序，我正在根据 Xcode 8.3.3 中单选问题的选定选项导航到问题。不幸的是，应用程序在设置导航规则时动态崩溃。在 Xcode 8.2.1 早期，我没有问题并且工作顺利。请让我知道我的代码出了什么问题，以下是崩溃日志：

无法将“（谓词：__ObjC.NSPredicate，destinationStepIdentifier：Swift.String）”（0x15fe50570）类型的值转换为“（resultPredicate：__ObjC.NSPredicate，destinationStepIdentifier：Swift.String）”（0x15fe60530）。 2017-10-10 07:37:57.530808 Turbo[7440:2981376] 无法将类型“（谓词：__ObjC.NSPredicate，destinationStepIdentifier：Swift.String）”（0x15fe50570）的值转换为“（resultPredicate：__ObjC.NSPredicate，destinationStepIdentifier : Swift.String)' (0x15fe60530)。

           //Question0
    let textChoiceOneText = NSLocalizedString("Choice 1", comment: "")
    let textChoiceTwoText = NSLocalizedString("Choice 2", comment: "")
    let textChoiceThreeText = NSLocalizedString("Choice 3", comment: "")

    // The text to display can be separate from the value coded for each choice:
    let textChoices = [
        ORKTextChoice(text: textChoiceOneText, value: "choice_1" as NSCoding & NSCopying & NSObjectProtocol),
        ORKTextChoice(text: textChoiceTwoText, value: "choice_2" as NSCoding & NSCopying & NSObjectProtocol),
        ORKTextChoice(text: textChoiceThreeText, value: "choice_3" as NSCoding & NSCopying & NSObjectProtocol)
    ]
    let answerFormat = ORKAnswerFormat.choiceAnswerFormat(with: .singleChoice, textChoices: textChoices)
    let questionStepzero = ORKQuestionStep(identifier: String(describing:"singlechoice0"), title: "titel", answer: answerFormat)

    //question1
    let question1 = ORKQuestionStep(identifier: "question1")
    question1.answerFormat = ORKBooleanAnswerFormat()
    //question2
    let question2 = ORKQuestionStep(identifier: "question2")
    question2.answerFormat = ORKBooleanAnswerFormat()

    //Question6
    let question6 = ORKQuestionStep(identifier: "question6")
    question6.answerFormat = ORKBooleanAnswerFormat()


    //Question 7
    let defaultDate = Date()
    let minDate = Date()
    let maxDate = Date()
    let nameQuestionStepTitle = "title message"
    let dateAnswer = ORKDateAnswerFormat(style:ORKDateAnswerStyle.date, defaultDate: defaultDate, minimumDate: minDate, maximumDate: maxDate, calendar: nil)
    let dataPickerQuestionStep7 = ORKQuestionStep(identifier: "datequestion7", title:nameQuestionStepTitle, answer: dateAnswer)


    let steps = [questionStepzero,question1, question2,question6,dataPickerQuestionStep7]
    let task = ORKNavigableOrderedTask(identifier: "task", steps: steps)

    let predicate1 = ORKResultPredicate.predicateForChoiceQuestionResult(with: ORKResultSelector(resultIdentifier: "singlechoice0"), matchingPattern: "choice_1")
    let predicate2 = ORKResultPredicate.predicateForChoiceQuestionResult(with: ORKResultSelector(resultIdentifier: "singlechoice0"), matchingPattern: "choice_2")
    let predicate3 = ORKResultPredicate.predicateForChoiceQuestionResult(with: ORKResultSelector(resultIdentifier: "singlechoice0"), matchingPattern: "choice_3")


    let singleChulesArray:NSMutableArray =  NSMutableArray()

    var dict:NSMutableDictionary = NSMutableDictionary()
    dict.setObject(predicate1, forKey: "predicateInstance" as NSCopying)
    dict.setObject("datequestion7", forKey: "Destination" as NSCopying)
    singleChulesArray.add(dict)
    dict = NSMutableDictionary()

    dict.setObject(predicate2, forKey: "predicateInstance" as NSCopying)
    dict.setObject("question2", forKey: "Destination" as NSCopying)
    singleChulesArray.add(dict)

    dict = NSMutableDictionary()
    dict.setObject(predicate3, forKey: "predicateInstance" as NSCopying)
    dict.setObject("question6", forKey: "Destination" as NSCopying)
    singleChulesArray.add(dict)



    //Static loading of Predicates and Destintionidentifiers
    /*
    let predicateRule1 = ORKPredicateStepNavigationRule(resultPredicatesAndDestinationStepIdentifiers: [
        (resultPredicate: predicate1, destinationStepIdentifier: "datequestion7"),
        (resultPredicate: predicate2, destinationStepIdentifier: "question2"),
        (resultPredicate: predicate3, destinationStepIdentifier: "question6")
        ])
    */

    print("singleChulesArray",singleChulesArray)

    //Dynamic loading of Predicates and Destination identifiers
    var stuff:[(predicate: NSPredicate, destinationStepIdentifier: String)] = [(predicate: NSPredicate, destinationStepIdentifier: String)]()
    for (_, PredicateDict) in singleChulesArray.enumerated()
    
        stuff += [(predicate: (PredicateDict as AnyObject).value(forKey: "predicateInstance") as! NSPredicate, destinationStepIdentifier: (PredicateDict as AnyObject).value(forKey: "Destination") as! String)]
    

    let predicateRule = ORKPredicateStepNavigationRule(resultPredicatesAndDestinationStepIdentifiers: stuff as! [(resultPredicate: NSPredicate, destinationStepIdentifier: String)])

    task.setNavigationRule(predicateRule, forTriggerStepIdentifier: "singlechoice0")
    let taskViewController = ORKTaskViewController(task: task, taskRun: nil)
    taskViewController.view.tintColor = TurboConstants.globalAccess.primaryClr
    taskViewController.delegate = self
    present(taskViewController, animated: true, completion: nil)

【参考方案1】：

您错误地使用了ORKPredicateStepNavigationRule 初始化程序。初始化程序将元组数组作为参数。您需要在初始化程序中传递元组的元素名称：

let predicateRule = ORKPredicateStepNavigationRule(resultPredicatesAndDestinationStepIdentifiers: [(resultPredicate: predicate1, destinationStepIdentifier: "datequestion7")])

或者使用多个元组：

let predicateRule = ORKPredicateStepNavigationRule(resultPredicatesAndDestinationStepIdentifiers: [
            (resultPredicate: predicate1, destinationStepIdentifier: "datequestion7"),
            (resultPredicate: predicate2, destinationStepIdentifier: "question2"),
            (resultPredicate: predicate3, destinationStepIdentifier: "question6"),
            ])

或动态（如您上面的代码）：

var stuff = [(resultPredicate: NSPredicate, destinationStepIdentifier: String)]()
for predicateDict in singleChulesArray

    guard
        let predicateDict = predicateDict as? [String: Any],
        let predicate = predicateDict["predicateInstance"] as? NSPredicate,
        let identifier = predicateDict["Destination"] as? String
        else  continue 
    stuff.append((resultPredicate: predicate, destinationStepIdentifier: identifier))

要消除崩溃，您只需将元组元素名称predicate 更改为正确的名称resultPredicate。当元组用作方法中的参数时，元素名称的命名必须与方法签名中的完全一致。否则你会崩溃。

我冒昧地在您的代码的那部分进行了更多更改。我删除了强制转换（这几乎不是一个好主意），而是使用了可选的展开。此外，我使用append 向stuff 数组添加一个新元组，而不是创建一个新数组（将元组作为其唯一元素），然后将该数组添加到 stuff 数组。

【讨论】：

是的，它仅适用于单个谓词的答案，但我无法导航具有多个选项（多个谓词）的单选问题。面临动态 JSON 框架中的问题。下面是实际代码

请查看编辑后的答案。这能解决你的问题吗？

var predicateAndDestinationIdentifierArray:[(predicate: NSPredicate, destinationString: String)] = [(predicate: NSPredicate, destinationString: String)]() for (index, PredicateDict) in singleChoicePredicateRulesArray.enumerated() let PredicateDic:NSMutableDictionary = PredicateDict as！ NSMutableDictionary predicateAndDestinationIdentifierArray += [(predicate: PredicateDic.value(forKey: "predicateInstance") as!NSPredicate, destinationString: PredicateDic.value(forKey: "Destination") as!String)]

让 singleChoicePredicate = ORKPredicateStepNavigationRule(resultPredicatesAndDestinationStepIdentifiers: predicateAndDestinationIdentifierArray as! [(resultPredicate: NSPredicate, destinationStepIdentifier: String)])

感谢您的回复，请查看我的代码，您能否告诉我它崩溃的原因。