UIImageView 显示不正确

Question

我已将 UIImageView 放置在我的自定义单元格中（Swift 3）：

let cell = self.tableView.dequeueReusableCell(withIdentifier: "Feedcell", for: indexPath) as! FruitTableViewCell

let hero: List_Feed
        hero = heroes[indexPath.row]

if(hero.photo==""){
            cell.cnHeight.constant = 0
            cell.cnTopMargin.constant = 0
            cell.cnBottomMargin.constant = 52
            cell.imgPhoto.image = UIImage()
            cell.imgPhoto.frame = CGRect(x: 0, y: 0, width: 0, height: 0)
        }else{
            cell.cnTopMargin.constant = 14
            cell.cnBottomMargin.constant = 50
            cell.imgPhoto.frame = CGRect(x: 0, y: 0, width: 0, height: 0)
            //displaying image
            Alamofire.request(hero.photo!).responseImage { response in
                debugPrint(response)
                if let image = response.result.value {
                    //let newWidth = containerView.frame.height * ratio
                    let bounds = UIScreen.main.bounds
                    let width = bounds.size.width
                    let imagewidth = image.size.width
                    let imageheight = image.size.height
                    let ot1 = width / imagewidth
                    let ot2 = round(ot1 * imageheight)
                    //let ot3 = round(ot2 / 2)
                    //let ot4 = ot3 - 12
                    //let ot5 = ot4 + 50
                    cell.cnHeight.constant = ot2
                    cell.imgPhoto.image = image
                }
            }
        }

它应该是这样显示的：

这是我向下滚动然后向上滚动时的显示方式：

（突然 uiimageview 覆盖了所有自定义单元格空间）

Answer 1

尝试添加

DispatchQueue.main.async {
    // all your ui code
}

您可能仍在后台线程中。