Question

我正在尝试检索用户的数据，以使用对象ID从_User类获取用户信息。我用过这个：

var data:NSMutableArray = NSMutableArray()
func loadData() {
    data.removeAllObjects()

    var profileQuery:PFQuery = PFUser.query()!
        profileQuery.getObjectInBackgroundWithId(userId, block: { (objects, error) -> Void in
            if error == nil {
                self.data.addObject(objects!)
            }
        })
    println(userId) // this is the userId as String.
    println(self.data)  ********* // empty array.
}

我在这里得到一个空数组data ..我也试过了，但同样的事情也发生在这里。：

 var profileQuery:PFQuery = PFUser.query()!
        profileQuery.whereKey("objectId", equalTo: userId)
        profileQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
            if let objects = objects {
                for object in objects {
                    self.data.addObject(object)   
                }   
            }
        }

Answer 1

请记住“findObjectsInBackgroundWithBlock”发生异步！您需要在块内部放置与数据相关的任何逻辑。

var profileQuery:PFQuery = PFUser.query()!
profileQuery.getObjectInBackgroundWithId(userId, block: { (objects, error) -> Void in
    if error == nil {
        self.data.addObject(objects!)
        println(self.data) //shouldn't be empty.
    }
})

Answer 2

撇开为什么你使用NSMutableArray作为单个PFUser对象的原因 - 你基本上希望看到self.data填充在错误的位置。用户将被添加到它（假设成功检索），内部闭包。所以做一些像：

var data:NSMutableArray = NSMutableArray()
func loadData() {
    data.removeAllObjects()

    var profileQuery:PFQuery = PFUser.query()!
    profileQuery.getObjectInBackgroundWithId(userId, block: { (objects, error) -> Void in
        if error == nil {
            self.data.addObject(objects!)
            println(self.data)  //...shouldn't be empty here
        } else {
            println("Error retrieving user: \(error.description")
        }
    })
}

使用“ObjectId”从Parse“_User”类中检索用户数据

2 个答案: