问题
I put UICollectionView inside table cell in Home page. Each category row has their contents image.
But, my problem is that when I run the app, the images under second row/second category do not show whenever I run the app.
The images will show after I click more button and it will goes to details UI. Then, I click on Back button and reach the Home page. At this time, the images shows properly.
I tried many codes but I don't know where it is wrong.
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
tableView.reloadData()
self.tableView.reloadData()
self.tableView.layoutIfNeeded()
}
override func viewDidAppear(_ animated: Bool) {
tableView.reloadData()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//getSearchWords()
DispatchQueue.main.async {
self.tableView.reloadData()
}
self.tableView.reloadData()
self.tableView.layoutIfNeeded()
}
override func viewDidLoad() {
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// debugPrint("HOme Table View Cell")
let cell = tableView.dequeueReusableCell(withIdentifier: "homecell") as! HomeCategoryRowCell
let list = sections[(indexPath as NSIndexPath).row]
cell.setCollectionViewDataSourceDelegate(self, forRow: indexPath.row)
cell.collectionViewOffset = self.storedOffsets[indexPath.row] ?? 0
DispatchQueue.main.async {
cell.categoryTitle.text = list.package_name
cell.mainAssociatedURL.text = list.package_url
}
cell.categoryTitle.font = UIFont.boldSystemFont(ofSize: 17.0)
cell.collectionView.tag = indexPath.row
cell.parentVC = self
cell.collectionView.reloadData()
return cell
}
extension Home : UICollectionViewDelegate, UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return sections[collectionView.tag].packageTable.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "videoCell", for: indexPath) as! HomeVideoCell
let list = sections[collectionView.tag].packageTable[indexPath.row]
if(list.poster_image_url != StringResource().posterURL){
let url = NSURL(string: list.poster_image_url)
do{
if let url = url {
_ = try Data(contentsOf:url as URL)
poster_url = list.poster_image_url
}
}catch let error {
//debugPrint("ERRor ::\(error)")
poster_url = StringResource().posterURL
}
}else{
poster_url = StringResource().posterURL
}
AsyncImageLoader.sharedLoader.imageForUrl(urlString: poster_url) { (image, url) -> () in
DispatchQueue.main.async(){
cell.movieTitle.text = list.name
if(url == StringResource().posterURL){
cell.imageView.image = UIImage(named: "sample_cover")
}else{
cell.imageView.image = image
}
}
}
// cell.layer.shouldRasterize = true
// cell.layer.rasterizationScale = UIScreen.main.scale
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Home Collection view at row \(collectionView.tag) selected index path \(indexPath)")
let list = sections[collectionView.tag].packageTable[indexPath.row]
self.prefs.set(list.poster_image_url, forKey: "poster_image_url")
self.prefs.set(list.name, forKey: "name")
self.prefs.set(list.assets_id, forKey: "VEDIO_ID")
debugPrint(list.name)
debugPrint(list.assets_id)
}
}
These above codes are written in Home.swift.
In HomeCell.swift,
class HomeCell : UITableViewCell {
var parentVC: UIViewController?
@IBOutlet weak var collectionView: UICollectionView!
@IBOutlet weak var categoryTitle: UILabel!
@IBOutlet weak var SeeAll: UIButton!
@IBOutlet weak var mainAssociatedURL: UILabel!
let prefs:UserDefaults = UserDefaults.standard
var catId: String! = ""
var associated_url: String!
override func awakeFromNib() {
super.awakeFromNib()
SeeAll.setTitle(NSLocalizedString("See All >", comment: ""), for: .normal)
SeeAll.titleLabel!.font = UIFont (name: "Tharlon", size: 14)
}
@IBAction func btnSeeAll(_ sender: Any) {
catId = categoryTitle.text!
associated_url = mainAssociatedURL.text!
self.prefs.setValue(1, forKey: "PROVIDER_ID")
self.prefs.set(catId, forKey: "PROVIDER_NAME")
self.prefs.set(associated_url, forKey: "associated_url")
}
override func layoutSubviews() {
super.layoutSubviews()
collectionView.collectionViewLayout.invalidateLayout()
}
}
extension HomeCategoryRowCell {
func setCollectionViewDataSourceDelegate<D: UICollectionViewDataSource & UICollectionViewDelegate>(_ dataSourceDelegate: D, forRow row: Int) {
self.collectionView.delegate = dataSourceDelegate
self.collectionView.dataSource = dataSourceDelegate
self.collectionView.tag = row
self.collectionView.setContentOffset(self.collectionView.contentOffset, animated:false) // Stops collection view if it was scrolling.
self.collectionView.reloadData()
}
var collectionViewOffset: CGFloat {
get { return collectionView.contentOffset.x }
set { collectionView.contentOffset.x = newValue }
}
}
Can anyone help me please?
回答1:
Edit controller like below, you are calling too many reloadData.
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
self.tableView.layoutIfNeeded()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//getSearchWords()
DispatchQueue.main.async {
self.tableView.reloadData()
}
self.tableView.layoutIfNeeded()
}
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
}
and add:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView .deselectRow(at: indexPath, animated: false)
}
来源：https://stackoverflow.com/questions/45074376/uicollection-view-inside-table-cell-does-not-show-images-in-swift-3