ios - 通过 createdAt 快速排序解析结果

Question

我查询存储在 parse.com 上的消息

let query = PFQuery(className: "Messages")
    query.whereKey("sender", equalTo: self.sender)
    query.whereKey("receiver", equalTo: self.receiver)
    query.orderByAscending("createdAt")
    query.findObjectsInBackgroundWithBlock {
        (objects: [AnyObject]?, error: NSError?) -> Void in

        if error == nil {
            var messages = [Int: [AnyObject]]()

            if let objects = objects as? [PFObject] {
                var i: Int = 0
                for object in objects {

                    var temp = [AnyObject]()

                    temp.append(object["sender"]!)
                    temp.append(object["receiver"]!)
                    temp.append(object.createdAt!)
                    temp.append(object["message"]!)

                    messages[i] = temp

                    i = i+1
                }
                print("Messages: \(messages)")
            }
        } else {
            print("Error!")
        }
    }

结果是这样的

Messages: [2: [Phil, Eff, 2015-08-27 15:05:04 +0000, three], 0: [Phil, Eff, 2015-08-27 15:04:57 +0000, one], 1: [Phil, Eff, 2015-08-27 15:05:00 +0000, two]]

似乎 query.orderByAscending("createdAt") 什么也没做？

Answer 1

createdAt 正在做它打算做的事情。这就是您将数据添加到对象的方式。

你需要放弃 int var 并简单地使用:

messages = temp

，因为您正在为对象中的每个对象运行一个循环。每条消息只能等于它的对应消息，没有理由为其指定索引

要将消息添加到数组，只需执行以下操作:

var messagesArray:NSMutableArray = []

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

      if let object = objects as ? [PFObject] {
           for object in objects {
           ...
           messages = temp
           self.messagesArray.addObject(messages)
           ...