UITable Cell 创建前两个的时候 UIView.transitionWithView 不起作用?

RT

求教 怎么回事啊?

table 出现之后 后面的动画都能执行,只有前两个刚创建的时候不执行动画.

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) ->  UITableViewCell {
    var bg:UIImage = UIImage(named: "BackgroundImage")!
    var myimg = UIImage(named: "download-loading")
    let link = self.tables[indexPath.row].pics?.first?.string!
    let cell = HomeCell(bgImg: bg, myimg: myimg!, target: self, data: tables[indexPath.row], url: tables[indexPath.row].url!, name: tables[indexPath.row].title!, description: tables[indexPath.row].description!)
    let url = NSURL(string: link!)
    if (self.myCache[indexPath.row]) {
        cell.myImage.sd_setImageWithURL(url, placeholderImage: myimg, options: SDWebImageOptions.LowPriority)
    }else{
        println("load cell")
        cell.myImage.alpha = 0.0
        self.myCache.insert(true, atIndex: indexPath.row)
        cell.myImage.sd_setImageWithURL(url, placeholderImage: myimg, options: SDWebImageOptions.LowPriority)
        cell.myImage.sd_setImageWithURL(url, placeholderImage: myimg!, completed: {
            (img) in
            UIView.transitionWithView(cell.myImage, duration: 0.5, options: UIViewAnimationOptions.TransitionCrossDissolve, animations: {
                cell.myImage.alpha = 1.0
                }, completion: nil)
        })

    }
 return cell
}