小编Ian*_*n33的帖子

我正在尝试将一个客观的C&CoreData应用程序移动到Swift和iOS,并通过迭代NSSet对象来打砖墙:

Xcode生成了这些类:

class Response: NSManagedObject {
    @NSManaged var responseText: String
    @NSManaged var score: NSNumber
    @NSManaged var answers: NSSet
    @NSManaged var question: Question
}

class Question: NSManagedObject {
    @NSManaged var questionText: String
    @NSManaged var questionType: String
    @NSManaged var qualifier: Qualifier
    @NSManaged var responses: NSSet
}

然后在第3课我要添加一个需要迭代NSSet的方法..

class Answer: NSManagedObject {

    @NSManaged var evaluation: Evaluation
    @NSManaged var response: Response

    func scoreGap() -> Int {
        var max = 0
        for aresponse in self.response.question.responses {

            // this next line throws an error
            var scoreVal …