ios - 解析错误 : PFObject does not have a member named 'createdAt'

Question

我被困在那个问题上。我已经阅读了 Parse 文档 ( https://parse.com/docs/ios/guide#queries-query-constraints )，但它对我帮助不大。

错误

当我尝试从 PFObject 获取“createdAt”或“updatedAt”时，出现以下错误:

['PFObject'] does not have a member named 'createdAt'

代码

这是(缩写)函数:

func loadCheckInData() {

    var query = PFQuery(className: "CheckIn")
    query.orderByDescending("createdAt")
    query.selectKeys(["firstName","lastName","updatedAt","createdAt"])

    query.findObjectsInBackgroundWithBlock({
        (objects: [AnyObject]?, error: NSError?) -> Void in

        if error == nil {

            println(objects)
            // Do something
            if let object = objects as? [PFObject] {
                println("\(object.createdAt)")                  <---- Error here
                self.CheckedPatients = Array(object.generate())
            }
        } else {
            // Log details of the failure
            println("Error: \(error!) \(error!.userInfo!)")
        } 
    }) 
}

然后我使用以下代码检索“CheckIn”Parse 类中的“firstName”、“lastName”(并尝试检索“createdAt”)

func collectionView(cellView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    // Add parse data
    if let value = CheckedPatients[indexPath.row]["lastName"] as? String {
        cell.cellLabelTwo.text = value
    }
    if let value = CheckedPatients[indexPath.row]["firstName"] as? String {
        cell.cellLabel.text = value
    }
    if let value = CheckedPatients[indexPath.row]["createdAt"] as? String {
        cell.cellDay.text = value
    }
    return cell
}

我调用函数

override func viewDidAppear(animated: Bool) {
    loadCheckInData()
}

事实上，我尝试了不同的方法来获取“createdAt”值，但我无法让它工作。有没有人有想法(如果可能的话，还有一个快速的解释)它可能很好。谢谢!

Answer 1

只是因为 updatedAt/createdAt 是所有 PFObjects 的属性，不需要使用键检索它，只需将其视为属性即可。