Swift中的NSCoding无法正确存档数据？

问题描述：

我对iOS开发一般比较陌生，但我正在编写这个应用程序。Swift中的NSCoding无法正确存档数据？

我有自定义对象“学期”，“课程”和“作业”。学期包含课程和课程阵列包含作业阵列。我可以正确归档学期和课程信息，但由于某些原因，分配信息无法读取。

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")

分配：

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") 
}

我不知道为什么，但是当我尝试无法读取的分配细节解码对象。

decoderObject有特殊方法解码Ints –

我的回答对你有帮助吗？任何反馈意见，谢谢 –

是的，它确实！谢谢你的帮助！！ –

答

我平时喜欢这个

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

翻译成你的问题将是这样的解码Int，改变你的Assignment类的init?(coder aDecoder: NSCoder)方法

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") 
    } 

}

希望这有助于

Swift中的NSCoding无法正确存档数据？

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