Swift ResearchKit HealthKit QuestionStep

Question

我目前正在 swift 中开发一个基于 ResearchKit 框架（用 Objective-c 编写）的医学研究应用程序。我目前正在尝试创建一个带有 HealthKit 问题的调查。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，第一行导致错误：

找不到接受“(characteristicType: String)”类型参数列表的“ORKHealthKitCharacteristicTypeAnswerFormat”的初始化程序

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。