【发布时间】：2018-03-22 18:50:34
【问题描述】：
所以我的 collectionView 有问题。目前我的设置是一个有两个部分的设置。每个部分中的数据都是从某个数据库中提取的，然后基于这些相应的部分中。
下面是我的主 homeFeedController 的代码
class HomeFeedController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
// let dropDownLauncher = DropDownLauncher()
let dispatchGroup = DispatchGroup()
var isFinishedPaging = false
var userLocation: CLLocation?
var allEvents = [Event]()
var eventKeys = [String]()
var featuredEvents = [Event]()
private let cellID = "cellID"
private let catergoryCellID = "catergoryCellID"
var images: [String] = ["gear1","gear4","snakeman","gear4","gear1"]
var images1: [String] = ["sage","sagemode","kyubi","Naruto_Part_III","team7"]
var featuredEventsHeaderString = "Featured Events"
var categories : [String] = ["Seize The Night","Seize The Day","21 & Up", "Friends Events"]
override func viewDidLoad() {
super.viewDidLoad()
// navigationItem.title = "Featured Events"
collectionView?.backgroundColor = .white
collectionView?.showsVerticalScrollIndicator = false
SVProgressHUD.dismiss()
grabUserLoc()
collectionView?.register(HomeFeedCell.self, forCellWithReuseIdentifier: cellID)
collectionView?.register(CategoryCell.self, forCellWithReuseIdentifier: catergoryCellID)
// reloadHomeFeed()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.setNavigationBarHidden(true, animated: false)
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
// self.view.removeFromSuperview()
}
deinit {
NotificationCenter.default.removeObserver(self)
print("EventDetailViewController class removed from memory")
}
@objc func grabUserLoc(){
LocationService.getUserLocation { (location) in
guard let currentLocation = location else {
return
}
PostService.showEvent(for: currentLocation, completion: { [unowned self](events) in
self.allEvents = events
print("Event count in PostService Closure:\(self.allEvents.count)")
DispatchQueue.main.async {
// self.dynamoCollectionView.reloadData()
//self.dynamoCollectionViewTop.reloadData()
}
})
PostService.showFeaturedEvent(for: currentLocation, completion: { [unowned self] (events) in
self.featuredEvents = events
print("Event count in Featured Events Closure is:\(self.featuredEvents.count)")
DispatchQueue.main.async {
// self.dynamoCollectionView.reloadData()
// self.dynamoCollectionViewTop.reloadData()
}
}
)
print("Latitude: \(currentLocation.coordinate.latitude)")
print("Longitude: \(currentLocation.coordinate.longitude)")
}
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.section == 0 {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellID, for: indexPath) as! HomeFeedCell
cell.sectionNameLabel.text = "Featured Events"
cell.featuredEvents = featuredEvents
return cell
}
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: catergoryCellID, for: indexPath) as! CategoryCell
cell.sectionNameLabel.text = categories[indexPath.item]
print(categories[indexPath.item])
print(indexPath.item)
cell.categoryEvents = allEvents
return cell
}
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 2
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if section == 1{
return 4
}
return 1
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if indexPath.section == 0 {
return CGSize(width: view.frame.width, height: 300)
}
return CGSize(width: view.frame.width, height: 290)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
if section == 0 {
return UIEdgeInsets(top: 5, left: 0, bottom: 10, right: 0)
}
return UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
}
在这个家庭提要控制器中创建的单元格在每个单元格中都有 collectionViews，它们创建了某种可滚动的网格布局。此外，每个单元格都会传递一个事件，其中包含渲染大部分单元格所需的信息。我的单元格的基本布局如下。
import UIKit
class CategoryCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
private let cellID = "cellID"
var categoryEvents: [Event]?{
didSet{
categoryCollectionView.reloadData()
}
}
var titles: String? {
didSet {
guard let titles = titles else {
return
}
sectionNameLabel.text = titles
}
}
let sectionNameLabel : UILabel = {
let sectionNameLabel = UILabel()
sectionNameLabel.font = UIFont(name:"HelveticaNeue-Bold", size: 16.0)
return sectionNameLabel
}()
let categoryCollectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .clear
return cv
}()
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
guard let currentEventCount = categoryEvents?.count else{
return 0
}
return currentEventCount
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellID, for: indexPath) as! CategoryEventCell
cell.event = categoryEvents?[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 200, height: frame.height - 30)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 0, left: 14, bottom: 0, right: 14)
}
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
@objc func setupViews(){
backgroundColor = .clear
addSubview(categoryCollectionView)
addSubview(sectionNameLabel)
sectionNameLabel.anchor(top: topAnchor, left: leftAnchor, bottom: nil, right: nil, paddingTop: 0, paddingLeft: 14, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
categoryCollectionView.anchor(top: sectionNameLabel.bottomAnchor, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
categoryCollectionView.delegate = self
categoryCollectionView.dataSource = self
categoryCollectionView.showsHorizontalScrollIndicator = false
categoryCollectionView.register(CategoryEventCell.self, forCellWithReuseIdentifier: cellID)
}
}
这个包含 collectionView 的单元格最终将特定事件传递给一个单元格，该单元格最终获取渲染自身所需的内容。代码如下。
import UIKit
import Firebase
import FirebaseDatabase
class CategoryEventCell: BaseRoundedCardCell {
var event: Event? {
didSet{
guard let currentEvent = event else {
return
}
guard let url = URL(string: currentEvent.currentEventImage) else { return }
backgroundImageView.af_setImage(withURL: url)
eventNameLabel.text = currentEvent.currentEventName.capitalized
}
}
public var backgroundImageView: CustomImageView = {
let firstImage = CustomImageView()
firstImage.clipsToBounds = true
firstImage.translatesAutoresizingMaskIntoConstraints = false
firstImage.contentMode = .scaleToFill
firstImage.layer.cornerRadius = 15
return firstImage
}()
let eventNameLabel : UILabel = {
let sectionNameLabel = UILabel()
sectionNameLabel.font = UIFont(name:"HelveticaNeue-Bold", size: 14.0)
return sectionNameLabel
}()
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
@objc func setupViews(){
backgroundColor = .clear
// setCellShadow()
addSubview(backgroundImageView)
addSubview(eventNameLabel)
backgroundImageView.setContentCompressionResistancePriority(UILayoutPriority(600), for: .vertical)
backgroundImageView.anchor(top: topAnchor, left: leftAnchor, bottom: eventNameLabel.topAnchor, right: rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
eventNameLabel.anchor(top: backgroundImageView.bottomAnchor, left: leftAnchor, bottom: bottomAnchor, right: nil, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
由于某种原因，该问题似乎与在应用程序启动时加载内容有关，但没有加载任何内容。但只要我滚动一切都开始加载。除此之外，当其他部分加载时，有一个部分甚至根本不加载任何内容。我希望所有单元格在我进入屏幕时而不是在滚动时加载它们的内容。如果这是一个新手错误，我深表歉意，但这并不是我想要的方式。也有一次用户界面实际上被锁定了。我当前的 UI 看起来像这样。任何帮助表示赞赏。这已经困扰了我好几个小时了
我知道当单元格在视图内时会加载 collectionViews，但问题是它们都不会加载，直到我向下或向上滚动，无论方向可能是什么。
【问题讨论】：
标签： ios swift uicollectionview