如果网络不好,我的应用程序在进入前景时卡住图标大约4-5秒。在几乎所有主要的加载页面中,我都从服务器获取图像。我没有任何关于applicationDidEnterBackground()
和applicationWillEnterForeground()
。缓慢的应用程序进入前景
在这里,在主视图控制器的代码,我有图像的集合视图:
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(homeReuseIdentifier, forIndexPath: indexPath)as! HomeViewCell
// Reload the collection view after insert item at indexPath
cvHome.reloadItemsAtIndexPaths([indexPath])
let entry = dataCell.infoCell[indexPath.row]
cell.backImageView.image = nil
let stringURL = "https://.....\(entry.filename)"
let image = UIImage(named: entry.filename)
cell.backImageView.image = image
if cell.backImageView.image == nil {
if let image = dataCell.cachedImage(stringURL) {
cell.backImageView.image = image
} else {
request = dataCell.getNetworkImage(stringURL) { image in
cell.backImageView.image = image
}
}
}
cell.titleLabel.text = entry.title
cell.authorLabel.text = entry.author
// Fix the collection view cell in size
cell.contentView.frame = cell.bounds
cell.contentView.autoresizingMask = [UIViewAutoresizing.FlexibleWidth, UIViewAutoresizing.FlexibleHeight]
// To edit the cell for deleting
cell.editing = editing
return cell
}
这是getNetworkImage功能与Alamofire:
func getNetworkImage(urlString: String, completion: (UIImage -> Void)) -> (ImageRequest) {
let queue = decoder.queue.underlyingQueue
let request = Alamofire.request(.GET, urlString)
let imageRequest = ImageRequest(request: request)
imageRequest.request.response(
queue: queue,
responseSerializer: Request.imageResponseSerializer(),
completionHandler: { response in
guard let image = response.result.value else {
return
}
let decodeOperation = self.decodeImage(image) { image in
completion(image)
self.cacheImage(image, urlString: urlString)
}
imageRequest.decodeOperation = decodeOperation
}
)
return imageRequest
}
是同步或异步的数据读取? – Harsh
我正在使用Alamofire,所以它是异步 – Giovanni