Swift ResearchKit HealthKit QuestionStep

Question

我目前正在研究基于ResearchKit框架（用Objective-c编写）的swift医学研究应用程序。我目前正在尝试使用HealthKit问题创建调查。我现在的代码是：

    let genderAnswerFormat = ORKHealthKitCharacteristicTypeAnswerFormat(characteristicType: HKCharacteristicTypeIdentifierBiologicalSex)
    let genderQuestionStepTitle = "What is your gender?"
    let genderQuestionStep = ORKQuestionStep(identifier: "genderQuestionStep", title: genderQuestionStepTitle, answer: genderAnswerFormat)
    steps += [genderQuestionStep]

但是，第一行会导致错误：

找不到＆＃39; ORKHealthKitCharacteristicTypeAnswerFormat＆＃39;的初始值设定项。接受类型＆＃39;（characteristicType：String）＆＃39;

的参数列表

Answer 1

您需要将标识符转换为HKObjectType，这是初始化程序的预期参数类型。