下午好，我的所有应用程序当前都在掉帧，我不确定如何修复它……有点丢失。
希望你们/加尔斯能向我指出正确的方向。
我目前正在使用Kingfisher从我的后端下载图像，除了向下滚动时滚动有点断断续续，一切正常。
控制器代码如下所示，也许有些问题。
我正在使用情节提要，并删除并添加了约束...但是我没有运气。
import UIKit
import Kingfisher
class WallpaperCVC: UICollectionViewController , UIViewControllerTransitioningDelegate {
var categoryId: String!
var categoryName: String!
var wallpaperBackend: Backend!
var result:CGSize!
// Header peralax
fileprivate let headerId = "headerId"
fileprivate let padding: CGFloat = 16
@IBOutlet var wpMain: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
self.title = self.categoryName // Name to the controller or section selected
// go go gadget data...
getData()
buttonGray()
setupCollectionViewLayout()
setupCollectionView()
}
func getData(){
GLOBAL_BACKEND_DATA.removeAll()
self.wallpaperBackend = Backend()
self.wallpaperBackend.getWallByIdData(id: self.categoryId) { (god) in
for post in god {
let postData = post as! NSDictionary
let wallpaperCVCId = postData.value(forKey: "id") as! String
let wallpaperCVCFile = postData.value(forKey: "file") as! String
let wallpaperCVCCategory = postData.value(forKey: "category") as! String
let wallpaperCVCDownload = Int(postData.value(forKey: "download") as! String)
GLOBAL_BACKEND_DATA.append(WallpaperModel(wallpaperModelId: wallpaperCVCId, wallpaperModelFile: wallpaperCVCFile, wallpaperModelCategoryId: wallpaperCVCCategory, wallpaperModelDownload: wallpaperCVCDownload!))
}
self.collectionView?.reloadData()
}
}
@IBAction func pressedAction(_ sender: UIButton) {
// do your stuff here
self.dismiss(animated: true, completion: nil)
print("you clicked on button \(sender.tag)")
}
func buttonGray(){
let myButton = UIButton() // if you want to set the type use like UIButton(type: .RoundedRect) or UIButton(type: .Custom)
let img = UIImage(named: "buttonA")
myButton.setImage(img, for: .normal)
// myButton.setTitleColor(UIColor.blue, for: .normal)
myButton.frame = CGRect(x: 15, y: 50, width: 100, height: 100)
// shadow
myButton.layer.shadowOpacity = 0.5
myButton.layer.shadowRadius = 4
myButton.layer.shadowOffset = CGSize(width: 0, height: 5)
myButton.addTarget(self, action: #selector(pressedAction(_:)), for: .touchUpInside)
// haptic feedback
myButton.isHaptic = true
myButton.hapticType = .impact(.medium)
//floatbutton like this
view.addSubview(myButton)
myButton.translatesAutoresizingMaskIntoConstraints = false
myButton.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor, constant: 10).isActive = true
myButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
}
// MARK: UICollectionViewDataSource
override func numberOfSections(in collectionView: UICollectionView) -> Int {
// You only need one section for now
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// Here call the wallpapers
return GLOBAL_BACKEND_DATA.count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
// pulling & going to the controller
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "wallpapers", for: indexPath) as! WallpaperCVCell
let godData = GLOBAL_BACKEND_DATA[indexPath.row]
let imageURL = String(format:"%@uploads/image/%@", BASE_BACKEND_URL,godData.wallpaperModelFile) // calling wallpaperModel controller
let escapedURL = imageURL.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)
let urls = URL(string:escapedURL!)
// if nothing load this...
let loadImage = UIImage(named: "skullLoading")
cell.collWallpaperImage.kf.setImage(with: urls, placeholder: loadImage)
cell.collWallpaperImage.kf.indicatorType = .activity // Showing a loading indicator while downloading
// lets count the downloads
let count = godData.wallpaperModelDownload as Int // calling wallpaperModel controller
cell.collectionCount.text = String(count) //collection view cell count label
cell.configure() // calling a function from the cell
return cell
}
// Lets move over to the next controller
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Tapped....Tapped go to the next controller..")
collectionView.deselectItem(at: indexPath, animated: true)
let vc = self.storyboard!.instantiateViewController(withIdentifier: "page") as! PageViewController
vc.position = indexPath.row
vc.categoryName = self.categoryName
vc.transitioningDelegate = self
vc.modalPresentationStyle = .custom
self.present(vc, animated: true, completion: nil)
}
}
// MARK: - CollectionView Delegate
extension WallpaperCVC {
// size images
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: IndexPath) -> CGSize {
result = CGSize(width: 187, height: 314)
if DeviceType.IS_IPHONE_5 {
result = CGSize(width: 160, height: 280)
}
if DeviceType.IS_IPHONE_6 {
result = CGSize(width: 187, height: 314)
}
if DeviceType.IS_IPHONE_6P {
result = CGSize(width: 207, height: 320)
}
if DeviceType.IS_IPHONE_4_OR_LESS {
result = CGSize(width: 151, height: 200)
}
return result;
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 15, left: 8, bottom: 5, right: 8)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 10
}
//size to all model screens to one.....NOW!!!!!!!!
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let width = UIScreen.main.bounds.width
return CGSize(width: (width - 28)/2, height: 350) // width & height are the same to make a square cell
}
}
// MARK: - CollectionView Layout Delegate
extension WallpaperCVC : UICollectionViewDelegateFlowLayout {
// Header peralax
fileprivate func setupCollectionViewLayout() {
let padding: CGFloat = 16
if let layout = wpMain.collectionViewLayout as? UICollectionViewFlowLayout {
layout.sectionInset = .init(top: padding, left: 0, bottom: padding, right: 0)
}
}
// Header peralax
fileprivate func setupCollectionView(){
wpMain.contentInsetAdjustmentBehavior = .never
wpMain.register(headerView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: headerId)
}
// Header peralax
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerId, for: indexPath)
return headerView
}
// Header peralax
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return .init(width: view.frame.width, height: 400)
}
}
该单元格看起来像这样
import UIKit
import Spring
import UICountingLabel
class WallpaperCVCell: UICollectionViewCell {
override func layoutSubviews() {
super.layoutSubviews()
// self.textLabel?.frame = self.bounds
}
func configure() {
layer.shouldRasterize = true
layer.rasterizationScale = UIScreen.main.scale
contentView.layer.cornerRadius = 7
contentView.layer.masksToBounds = true
// contentView.layer.borderWidth = 1.0
// contentView.layer.borderColor = UIColor.black.cgColor
}
@IBOutlet weak var collectionCount: UICountingLabel!
@IBOutlet weak var collWallpaperImage: UIImageView!
override func awakeFromNib() {
super.awakeFromNib()
}
}
&&这是视频...最初的滚动滞后然后消失，但每次都会播放
编辑：最后，我重新设置了Kingfisher并安装了SDWebImage，这解决了该问题。
答案 0 :(得分：0)
根据给定的代码，没有什么应该引起延迟。如果您可以分享一段有关时滞的简短视频，可以帮助您更好地理解问题。
另外，如果您可以共享cell.configure（）方法中的代码也有帮助的话。
我确实为您提供了一些建议，可能会有所帮助，您可以尝试一下。
首先您可以移动设备检查
if DeviceType.IS_IPHONE_5 {
result = CGSize(width: 160, height: 280)
}
if DeviceType.IS_IPHONE_6 {
result = CGSize(width: 187, height: 314)
}
if DeviceType.IS_IPHONE_6P {
result = CGSize(width: 207, height: 320)
}
if DeviceType.IS_IPHONE_4_OR_LESS {
result = CGSize(width: 151, height: 200)
}
在viewDidLoad中，这将帮助您的集合视图布局更快地调整单元格的大小，而不必每次用户滚动时都进行检查
类似这样的东西
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: IndexPath) -> CGSize {
return result;
}
和
override func viewDidLoad() {
super.viewDidLoad()
self.title = self.categoryName // Name to the controller or section selected
setupDeviceSize()
// go go gadget data...
getData()
buttonGray()
setupCollectionViewLayout()
setupCollectionView()
}
func setupDeviceSize(){
if DeviceType.IS_IPHONE_5 {
result = CGSize(width: 160, height: 280)
}
if DeviceType.IS_IPHONE_6 {
result = CGSize(width: 187, height: 314)
}
if DeviceType.IS_IPHONE_6P {
result = CGSize(width: 207, height: 320)
}
if DeviceType.IS_IPHONE_4_OR_LESS {
result = CGSize(width: 151, height: 200)
}
}
第二，您可以为占位符图像创建全局变量
let loadImage = UIImage(named: "skullLoading")
并在cellForItemAtIndexpath中使用它，这将在每次调用cellForItemAtIndexpath时再次保存占位符图像的加载。
您应始终将cellForItemAtIndexpath保持尽可能浅，以实现流畅的滚动体验。
希望这会有所帮助。