swift - 解析 PFQueryTableViewConntroller 不加载图像

Question

我正在使用 parse 的 PFQueryTableViewController，在检索日期时似乎一切正常，除了 UIImageView 没有加载数据库中的文件。文本和其他所有内容都会加载，除了文件。这是我的代码：

import UIKit
import Parse
import ParseUI

class PostsTableViewController: PFQueryTableViewController {

    override func queryForTable() -> PFQuery {

        let query = PFQuery(className: "Posts")
        query.cachePolicy = .CacheElseNetwork
        query.orderByDescending("createdAt")
        return query
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath, object: PFObject?) -> PFTableViewCell? {

        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! PostsTableViewCell

        let posterUsernameText = object?.objectForKey("createdBy") as? String
        cell.posterUsername.setTitle("\(posterUsernameText)", forState: .Normal)

        cell.msgTextView.text = object?.objectForKey("text") as? String

        let imageFile = object?.objectForKey("image") as? PFFile
        cell.cellImageView.file = imageFile
        cell.imageView?.loadInBackground()

        return cell

    }

    override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {

        if indexPath.row + 1 > self.objects?.count {

            return 44

        }

        let height = super.tableView(tableView, heightForRowAtIndexPath: indexPath)
        return height
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

        if indexPath.row + 1 > self.objects?.count {

            self.loadNextPage()
            tableView.deselectRowAtIndexPath(indexPath, animated: true)

        } else {

            self.performSegueWithIdentifier("showDetail", sender: self)

        }
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        if segue.identifier == "showDetail" {



        }

    }

}

Answer 1

我认为您应该更改此代码：

let imageFile = object?.objectForKey("image") as? PFFile
cell.cellImageView.file = imageFile
cell.imageView?.loadInBackground()

到：

if let imageFile = object?.objectForKey("image") as? PFFile {
                imageFile.getDataInBackgroundWithBlock({ (imgContent:NSData?, error:NSError?) -> Void in
                    if error != nil {
                        print(error?.description)
                    }else if let imgContent = imgContent {
                        cell.imageView?.image = UIImage(data: imgContent)!
                    }
                })
            }

Answer 2

在弄乱了代码之后，这似乎奏效了。希望这对将来的其他人有所帮助，以下是我所做的更改：

代替：

let imageFile = object?.objectForKey("image") as? PFFile
cell.cellImageView.file = imageFile
cell.imageView?.loadInBackground()

我应该是：

    let imageFile = object?.objectForKey("image") as? PFFile
    cell.cellImageView.file = imageFile
    cell.cellImageView?.loadInBackground()