問題描述:
This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.

問題代碼 ：

func loadImage(imageURL:String){
        print("image url->",imageURL)
        let url = NSURL(string: imageURL)
        let data = try? NSData(contentsOfURL: url!, options: NSDataReadingOptions.DataReadingMappedIfSafe)
        let image = UIImage(data: data!)
        self.images.append(image)
    }

因為執(zhí)行

NSData(contentsOfURL: url!, options: NSDataReadingOptions.DataReadingMappedIfSafe)

會阻塞主進程，因此我們需要自行異步調(diào)用此方法來解決問題

改成下面的樣子后就好了

因為是一組圖片，所以我們增加一個異步加載隊列組來管理加載
func loadImages(images:[String]) {
        let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
        let queueGroup = dispatch_group_create()
        dispatch_group_async(queueGroup, queue, {
            for imageURL in images{
                self.loadImage(imageURL)
            }
        })
        dispatch_group_notify(queueGroup, dispatch_get_main_queue(), {
            //將加載完成后的圖片添加到視圖
            self.addImages()
        })
    }

func loadImage(imageURL:String){
        print("image url->",imageURL)
        let url = NSURL(string: imageURL)
        let data = try? NSData(contentsOfURL: url!, options: NSDataReadingOptions.DataReadingMappedIfSafe)
        let image = UIImage(data: data!)
        self.images.append(image!)
    }

更具體的線程講解可以參考這篇文章或者自行搜索
http://blog.csdn.net/totogo2010/article/details/8016129