无法在DataController Init中的属性初始化程序错误中使用实例成员

Question

我有一个数据控制器，它应该接收数据，然后将其放入UITableViewDataSource。我似乎无法访问init中的变量。

如果我取消注释init中的var sections声明，那么我得到一个错误，“类型DataController1的值没有成员节”

有人能告诉我我错过了什么吗？

相关的代码行如下：

class DataController1: NSObject, DataController {

    struct Section {
        let type: SectionTypeEnum
        let rows: [Any]
    }

    let contactData: ContactData
    var section1: [Section1]!
    var section2: [Section2]!
    var section3: [Section3]!
//    var sections = [Section]!


    init(contactData: ContactData) {
        self.contactData = contactData

        self.section1 = self.contactData.list1
        self.section2 = self.contactData.list2
        self.section3 = self.contactData.list3

//        var sections: [Section] = [
//            Section(type: .section1, rows: section1),
//            Section(type: .section2, rows: section2),
//            Section(type: .section3, rows: section3),
//]

    }



    var sections: [Section] = [

        Section(type: .section1, rows: section1),
//Cannot use instance member 'section1' within property initializer; property initializers run before 'self' is available
// current error
        Section(type: .section2, rows: section2),
        Section(type: .section3, rows: section3),
    ]
}

Answer 1

如注释中所述发生错误是因为您无法声明具有初始值的属性，这取决于彼此。

我建议只支持init(contactData方法。

永远不要将属性声明为隐式展开的可选项，它们在带有非可选值的init方法中初始化。如果它们应该是可选的，则将它们声明为常规可选（?）

class DataController1: NSObject, DataController {

    struct Section {
        let type: SectionTypeEnum
        let rows: [Any]
    }

    let contactData: ContactData
    var section1: [Section1]
    var section2: [Section2]
    var section3: [Section3]
    var sections: [Section]


    init(contactData: ContactData) {
        self.contactData = contactData

        section1 = self.contactData.list1
        section2 = self.contactData.list2
        section3 = self.contactData.list3
        sections = [Section(type: .section1, rows: section1),
                    Section(type: .section2, rows: section2),
                    Section(type: .section3, rows: section3)]
    }
}