Swift 中的 NSCoding 没有正确归档数据？

Question

总的来说，我对 iOS 开发还比较陌生，但我正在编写此应用程序的代码。

我有自定义对象 "Semester"、"Course" 和 "Assignments"。学期包含课程数组，课程包含作业数组。我能够正确存档学期和课程信息，但由于某些原因无法读取作业信息。

学期：

required init?(coder aDecoder: NSCoder) {
    self.name = ""

    super.init()

    if let archivedName = aDecoder.decodeObject(forKey: "name") as? String {
        name = archivedName
    }
    if let archivedCourses = aDecoder.decodeObject(forKey: "courses") as? [Course] {
        courses = archivedCourses
    }
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(name, forKey: "name")
    aCoder.encode(courses, forKey: "courses")
}

课程：

required init?(coder aDecoder: NSCoder) {
    self.name = ""
    super.init()

    if let archivedName = aDecoder.decodeObject(forKey: "courseName") as? String {
        name = archivedName
    }
    if let archivedAssignments = aDecoder.decodeObject(forKey: "assignments") as? [Assignment] {
        assignments = archivedAssignments
    }
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(name, forKey: "courseName")
    aCoder.encode(assignments, forKey: "assignments")

作业：

required init?(coder aDecoder: NSCoder) {
    self.name = ""
    self.grade = 0
    self.weight = 0
    super.init()

    if let archivedName = aDecoder.decodeObject(forKey: "assignmentName") as? String, let archivedGrade = aDecoder.decodeObject(forKey: "assignmentGrade") as? Int, let archivedWeight = aDecoder.decodeObject(forKey: "assignmentWeight") as? Int {
        name = archivedName
        grade = archivedGrade
        weight = archivedWeight
    }
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(name, forKey: "assignmentName")
    aCoder.encode(grade, forKey: "assignmentGrade")
    aCoder.encode(weight, forKey: "assignmentWeight")
}

我不确定为什么，但是当我尝试解码对象时无法读取分配详细信息。

Answer 1

我通常这样解码Int

if decoder.containsValue(forKey: "teamNumber"){
    self.teamNumber = decoder.decodeInteger(forKey: "teamNumber")
}

翻译成你的issue会这样，改一下你Assignment的init?(coder aDecoder: NSCoder)方法class

required init?(coder aDecoder: NSCoder) {

    self.name = ""
    self.grade = 0
    self.weight = 0
    super.init()

    if let archivedName = aDecoder.decodeObject(forKey: "assignmentName") as? String{
      self.name = archivedName
    } 

    if decoder.containsValue(forKey: "assignmentGrade"){
        self.grade = decoder.decodeInteger(forKey: "assignmentGrade")
    }

    if decoder.containsValue(forKey: "assignmentWeight"){
        self.weight = decoder.decodeInteger(forKey: "assignmentWeight")
    }

}

希望对您有所帮助

Swift 中的 NSCoding 没有正确归档数据？

NSCoding in Swift not archiving data properly?

ios

swift

archive

nscoding