Question

我构建了一个IOS应用程序，不知怎的，我必须在swift类中进行聚合，但每次我想获取数据时，它总是返回错误。似乎我的数据总是返回一个零结果。

我想在视图控制器类中推送DoctorList成员对象（schedule）我已经创建了对象，我也调用了init（）函数。但是，当我按下（或调用）DoctorList类的init函数并传递ScheduleList数组时，doctorlist类中的schedule成员的内容将始终为空。

所以当我试图获得时间表时，它将返回一个零结果。

每个人都可以告诉我我做错了什么，因为我已经更改了代码，但它仍然没有结果。

我有两个这样的课程

class DoctorList: NSObject {
var DoctorID: String?
var DoctorName: String?
var SpecialtyID: String?
var SpecialtyName: String?
var ImageURL: String?
var Schedule: [ScheduleList]?

init(_ DoctorID:String, _ DoctorName:String, _ SpecialtyID:String, _ SpecialtyName:String, _ ImageUrl:String, _ Schedule:[ScheduleList] ){
    self.DoctorID = DoctorID
    self.DoctorName = DoctorName
    self.SpecialtyID = SpecialtyID
    self.SpecialtyName = SpecialtyName
    self.ImageURL = ImageUrl
    for sc in Schedule {
        self.Schedule?.append(ScheduleList(sc.DoctorID!, sc.DayName!, sc.FirstHour!, sc.LastHour!))
    }

}

var getSchedule: [ScheduleList] {
    get {
        return self.Schedule!
    }

}

和这一个

class ScheduleList: NSObject {
var DoctorID: String?
var DayName: String?
var FirstHour: String?
var LastHour: String?

init(_ DoctorID:String, _ DayName:String, _ FirstHour:String, _ LastHour:String ){
    self.DoctorID = DoctorID
    self.DayName = DayName
    self.FirstHour = FirstHour
    self.LastHour = LastHour
}

计划的返回值始终为空

对不起，有人可以提出如何在swift中创建全局变量的建议吗？

Answer 1

您尚未初始化Schedule数组。

循环中的append语句永远不会执行：

for sc in Schedule {
    // self.Schedule is nil so anything come after the question mark does not run
    self.Schedule?.append(ScheduleList(sc.DoctorID!, sc.DayName!, sc.FirstHour!, sc.LastHour!))
}

要修复它，请在使用前初始化数组：

self.Schedule = [ScheduleList]()
for sc in Schedule {
    self.Schedule?.append(ScheduleList(sc.DoctorID!, sc.DayName!, sc.FirstHour!, sc.LastHour!))
}

此外，您的代码很难阅读：

无处不在的选择！您应该决定哪些属性可以和不可以为零并删除不必要的?和!
Swift中的约定对于变量名称为lowerCamelCase，对于类名称为CamelCase
除非您想要ObjC世界的某些东西，无论是使用ObjC还是使用KVO，否则无需继承NSObject

Answer 2

刚刚注意到，来自@CodeDifferent的建议应该是恰当和有用的。这是因为您尚未初始化Schedule

中的DoctorList

init(_ DoctorID:String, _ DoctorName:String, _ SpecialtyID:String, _ SpecialtyName:String, _ ImageUrl:String, _ Schedule:[ScheduleList] ){
        self.DoctorID = DoctorID
        self.DoctorName = DoctorName
        self.SpecialtyID = SpecialtyID
        self.SpecialtyName = SpecialtyName
        self.ImageURL = ImageUrl

        // Use this for init an empty array and append the content
        self.Schedule = [ScheduleList]()
        self.Schedule?.append(contentsOf: Schedule)
    }

结果的一个例子：

let schedule = ScheduleList("scheduleId", "name", "1st", "last")
let doctorList = DoctorList("docId", "docName", "specId", "scpecName", "imgURL", [schedule])
if let list = doctorList.Schedule {
    print("\(list[0].DoctorID)")
}

在Swift类中获取和设置数组

2 个答案: