ios - 快速读取 JSON 解析到 NSArray 时出现段错误

Question

有一种方法用于从 json 填充领域数据库:

func parseJSON(data: NSData) -> NSArray? {
    do {
        let array: NSArray = try NSJSONSerialization.JSONObjectWithData(data, options: .MutableContainers) as! NSArray

        return array
    } catch _ {
        return nil
    }
}
//parameter came from previous method
func updateDatabaseFromParsedJson(parsedJson: NSArray) {
    let realm = try! Realm()
    try! realm.write {
        realm.deleteAll()
    }
    for i in 0..<parsedJson.count {
        let deviceObject = parsedJson[i]

        let name = deviceObject["name"] as! String
        let id = deviceObject["id"] as! Int

        var device = Device()
        device.name = name
        device.id = id
        try! realm.write {
            realm.add(device)
        }
        var deviceMeasuresArray = deviceObject["measures"] as! NSArray
        for i in 0..<deviceMeasuresArray.count {
            var measureObject = deviceMeasuresArray[i]
            var measure = Measure()
            measure.slug = measureObject["name"]
            measure.device = device
            measure.localize()
            try! realm.write {
                realm.add(measure)
            }
            var measureEntriesArray = measureObject["averages"] as! NSArray
            for i in 0..<measureEntriesArray.count {
                var entryObject = measureEntriesArray[i]
                var entry = PeriodAverage()
                entry.measure = measure
                entry.value = entryObject["value"]
                entry.start = NSDate.parse(entryObject["start"])
                entry.end = NSDate.parse(entryObject["end"])
                entry.length = entryObject["length"]
                try! realm.write {
                    realm.add(entry)
                }
            }
        }
    }
}

extension NSDate {
    class func parse(dateString: String) -> NSDate {

        let format = "yyyy-MM-dd'T'HH:mm:ss'Z'"
        let formatter = NSDateFormatter()
        formatter.dateFormat = format
        return formatter.dateFromString(dateString)!
    }
}

JSON 本身 http://188.166.51.200/api/v1/actual_data/

编译时出现错误错误:无法执行命令:段错误:11

我错在哪里以及如何正确解析我的 json？我认为问题出在 json 字段强制解析为对象的行中，但我是 swift 新手，无法准确确定错误。

Answer 1

您显然遇到了编译器问题(您应该 report to Apple )，尽管它很容易解决。如果您正在使用 Swift，您应该尽可能使用 Swift 集合类型而不是 Foundation 集合类型(即，Array 而不是 NSArray) 允许更多的类型信息。此外，当您转换从 JSON 中获取的一些值时，您并没有转换所有值。添加此附加类型信息将使编译器运行并解决该问题。我建议进行以下编辑:

func updateDatabaseFromParsedJson(parsedJson: Array<AnyObject>) {
    let realm = try! Realm()
    try! realm.write {
        realm.deleteAll()
    }
    for i in 0..<parsedJson.count {
        let deviceObject = parsedJson[i] as! Dictionary<String, AnyObject>

        let name = deviceObject["name"] as! String
        let id = deviceObject["id"] as! Int

        var device = Device()
        device.name = name
        device.id = id
        try! realm.write {
            realm.add(device)
        }
        var deviceMeasuresArray = deviceObject["measures"] as! Array<AnyObject>
        for i in 0..<deviceMeasuresArray.count {
        var measureObject = deviceMeasuresArray[i] as! Dictionary<String, AnyObject>
            var measure = Measure()
            measure.slug = measureObject["name"] as! String // I'm guessing on the type here
            measure.device = device
            measure.localize()
            try! realm.write {
                realm.add(measure)
            }
            var measureEntriesArray = measureObject["averages"] as! Array<AnyObject>
            for i in 0..<measureEntriesArray.count {
                var entryObject = measureEntriesArray[i] as! Dictionary<String, AnyObject>
                var entry = PeriodAverage()
                entry.measure = measure
                entry.value = entryObject["value"] as! String // Guessing on the type here also
                entry.start = NSDate.parse(entryObject["start"] as! String)
                entry.end = NSDate.parse(entryObject["end"] as! String)
                entry.length = entryObject["length"] as! String // Again, guessing on the type here
                try! realm.write {
                    realm.add(entry)
                }
            }
        }
    }
}

与编译器问题无关，您还可以使用 for-in 循环使您的代码更像 Swift。您可以在 For-In Loops 中阅读有关它们的更多信息。节Control Flow The Swift Programming Language的章节.