Question

我正在构建一个用于创建使用解析作为后端的事件的应用。主界面是一个带有自定义单元格的集合视图，在翻转时会显示一个UIImageViews数组作为IBOutlet集合添加到单元格文件中。

 @IBOutlet var imageViewArray: [UIImageView]!

在event.getDataInBackground块里面我有这个代码，由于某些原因它没有被调用，我认为它会一旦有效，但是有人知道它是什么吗？谢谢！

            //gets profile pictures for image view array on back of cell

            if let attendeeArray = event?.objectForKey("attendees") as? [PFUser] {

                for var index = 0; index < attendeeArray.count; ++index {
                    let profileImageView = cell.imageViewArray[index]
                    let usr : PFUser = (attendeeArray[index] as PFUser?)!

                    if let picture = usr.objectForKey("profilePicture") as? PFFile {

                        picture.getDataInBackgroundWithBlock({ (data, error) -> Void in

                            profileImageView.image = UIImage(data: data!)

                        })

                    }

                }

            }

索引路径方法行的整个单元格（创建者图像显示并被调用但参加者数组部分不是）。

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

    //sets up cell

    let cell : EventCell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! EventCell

    //adds attend action

    cell.attendButton.addTarget(self, action: "buttonTapped:", forControlEvents: UIControlEvents.TouchUpInside)

    //queries parse for events

    let event = events?[indexPath.row]

    event?.eventImage.getDataInBackgroundWithBlock({ (data, error) -> Void in

        if let data = data, image = UIImage(data: data) {

            cell.eventBackgroundImage.image = image
            cell.eventTitleLabel.text = event?.eventTitle

            //gets profile picture of events creator

            if let eventCreator = event?.objectForKey("user") as? PFUser {
                if let creatorImage = eventCreator.objectForKey("profilePicture") as? PFFile {

                        creatorImage.getDataInBackgroundWithBlock({ (data, error) -> Void in

                        cell.creatorImageView.image = UIImage(data: data!)

                    })
                }
            }

            //gets profile pictures for image view array on back of cell

            if let attendeeArray = event?.objectForKey("attendees") as? [PFUser] {

                for var index = 0; index < attendeeArray.count; ++index {
                    let profileImageView = cell.imageViewArray[index]
                    let usr : PFUser = (attendeeArray[index] as PFUser?)!

                    if let picture = usr.objectForKey("profilePicture") as? PFFile {

                        picture.getDataInBackgroundWithBlock({ (data, error) -> Void in

                            profileImageView.image = UIImage(data: data!)

                        })

                    }

                }

            }


            //sets correct category for cell image

            if event?.category == "" {
                cell.categoryImageView.image = nil
            }

            if event?.category == "The Arts" {
                cell.categoryImageView.image = UIImage(named: "Comedy")
            }

            if event?.category == "The Outdoors" {
                cell.categoryImageView.image = UIImage(named: "Landscape")
            }

            if event?.category == "Other" {
                cell.categoryImageView.image = UIImage(named: "Dice")
            }

            if event?.category == "Sports" {
                cell.categoryImageView.image = UIImage(named: "Exercise")
            }

            if event?.category == "Academics" {
                cell.categoryImageView.image = UIImage(named: "University")
            }

            if event?.category == "Science" {
                cell.categoryImageView.image = UIImage(named: "Physics")
            }

            if event?.category == "Entertainment" {
                cell.categoryImageView.image = UIImage(named: "Bowling")
            }

            if event?.category == "Food & Drinks" {
                cell.categoryImageView.image = UIImage(named: "Food")
            }

            if let date = event?.eventDate {
                let dateFormatter = NSDateFormatter()
                dateFormatter.dateFormat = "yyyy-MM-dd"

                cell.eventDescriptionLabel.text = event?.eventDescription
                cell.eventDateLabel.text = dateFormatter.stringFromDate(date)
            }
        }
    })

    cell.layer.cornerRadius = 20

    return cell

}

已编辑：

            //gets profile pictures for image view array on back of cell

            if let attendeeArray = event?.objectForKey("attendees") as? [PFUser] {

                for var index = 0; index < attendeeArray.count; ++index {
                    let profileImageView = cell.imageViewArray[index]
                    let usr : PFUser = (attendeeArray[index] as PFUser?)!


                        usr.fetchIfNeededInBackgroundWithBlock({ (object: PFObject?, error: NSError?) -> Void in
                            if let picture = object!.objectForKey("profilePicture") as? PFFile {
                                picture.getDataInBackgroundWithBlock({ (data, error) -> Void in
                                    profileImageView.image = UIImage(data: data!)
                                })
                            }
                        })

                }

            }

Answer 1

你需要先获取usr才能获得图片

usr.fetchIfNeededInBackgroundWithBlock({ (object: PFObject?, error: NSError?) -> Void in
            if let picture = object.objectForKey("profilePicture") as? PFFile {
                picture.getDataInBackgroundWithBlock({ (data, error) -> Void in
                    profileImageView.image = UIImage(data: data!)
                })
            }
        })

使用UIImageView数组同步解析对象数组

1 个答案: