TableView扩展swift 2图像隐藏

Question

我在扩展程序中使用Swift 2和XCode 7.2。我正在使用包含图像和标签的单元格渲染UITableView，问题是图像是隐藏的！我不知道为什么！请有人帮帮我吗

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell
    cell.textLabel!.textColor = UIColor.whiteColor()


    let query = PFQuery(className:"Recipe")
    query.orderByDescending("createdAt")
    query.findObjectsInBackgroundWithBlock {
        (objects: [PFObject]?, error: NSError?) -> Void in
        if error == nil {
            print("Success retrieved \(objects!.count) scores.")
            if let objects = objects {
                for object in objects {
                    let a:String = object.objectForKey("title") as! String
                     self.contentString.append(a)
                }
            }
            let cellImg : UIImageView = UIImageView(frame: CGRectMake(5, 5, 50, 50))
            cellImg.backgroundColor=UIColor.whiteColor()
           cellImg.image = UIImage(named: "jj.png")
          //  cell.addSubview(cellImg)

        cell.imageView!.image=cellImg.image
        cell.textLabel!.text = self.contentString[indexPath.row]
        }}
    return cell
}