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这是我第一次使用集合视图，我挣扎了很多。我在“setupView”函数中设置了一个集合视图布局，然后实现了典型的视图方法，如numberOfSections和cellForRowAtIndexPath。现在，我只是想让集合视图工作，所以我只是使用我工作区中已有的图像，而不是从API获取图片（稍后会发布）。集合视图单元格不显示在集合视图中？
这是我使用的代码。为什么它不显示黑屏以外的任何内容？
import UIKit
import Alamofire
import AlamofireImage
class PhotoBrowserCollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let goldenWordsYellow = UIColor(red: 247.00/255.0, green: 192.00/255.0, blue: 51.00/255.0, alpha: 0.5)
@IBOutlet weak var menuButton:UIBarButtonItem!
@IBOutlet var picturesCollectionView: UICollectionView!
var pictureObjects = NSMutableOrderedSet(capacity: 1000)
var customRefreshControl = UIRefreshControl()
let PhotoBrowserCellIdentifier = "PhotoBrowserCell"
var dateFormatter = NSDateFormatter()
var nodeIDArray = NSMutableArray()
var timeStampDateString : String!
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView!.registerClass(PhotoBrowserCollectionViewCell.self, forCellWithReuseIdentifier: PhotoBrowserCellIdentifier)
self.revealViewController().rearViewRevealWidth = 280
collectionView!.delegate = self
collectionView!.dataSource = self
customRefreshControl = UIRefreshControl()
customRefreshControl.backgroundColor = goldenWordsYellow
customRefreshControl.tintColor = UIColor.whiteColor()
self.picturesCollectionView!.addSubview(customRefreshControl)
navigationController?.setNavigationBarHidden(false, animated: true)
navigationItem.title = "Pictures"
setupView()
populatePhotos()
self.dateFormatter.dateFormat = "dd/MM/yy"
}
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5 // setting an arbitrary value in case pictureObjects is not getting correctly populated
}
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(PhotoBrowserCellIdentifier, forIndexPath: indexPath) as! PhotoBrowserCollectionViewCell
cell.imageView.image = UIImage(named: "mail")
return cell
}
这里是我的setupView函数。
override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("ShowPhoto", sender: (self.pictureObjects.objectAtIndex(indexPath.item) as! PictureElement).imageURL)
}
func setupView() {
navigationController?.setNavigationBarHidden(false, animated: true)
let layout = UICollectionViewFlowLayout()
let itemWidth = (view.bounds.size.width - 2)/3
layout.itemSize = CGSize(width: itemWidth, height: itemWidth)
layout.minimumInteritemSpacing = 1.0
layout.minimumLineSpacing = 1.0
collectionView!.collectionViewLayout = layout
navigationItem.title = "Pictures"
customRefreshControl.tintColor = UIColor.whiteColor()
customRefreshControl.addTarget(self, action: "handleRefresh", forControlEvents: .ValueChanged)
self.collectionView!.addSubview(customRefreshControl)
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSizeMake(120, 120)
}
一切看起来真的搞糟了故事板。我正在使用UICollectionViewController swift类（不是UIViewController + collectionView组合），我真的不知道应该使用哪个插座。这里是我的整个视图控制器上连接列表：
最后，这里是我最简单的视图层次。
我真的不知道为什么收集视图无法正常工作。有任何想法吗 ？
编辑1：我改变了很多代码，最终让我的collectionView工作。对于那些正在努力解决类似问题的人来说，这里是我用于collectionView的所有代码。也许这将帮助您解决在自己的CollectionView代码问题
import UIKit
import Alamofire
import AlamofireImage
class PhotoBrowserCollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let goldenWordsYellow = UIColor(red: 247.00/255.0, green: 192.00/255.0, blue: 51.00/255.0, alpha: 0.5)
@IBOutlet weak var menuButton:UIBarButtonItem!
@IBOutlet var picturesCollectionView: UICollectionView!
var temporaryPictureObjects = NSMutableOrderedSet(capacity: 1000)
var pictureObjects = NSMutableOrderedSet(capacity: 1000)
var goldenWordsRefreshControl = UIRefreshControl()
var revealViewControllerIndicator : Int = 0
let imageCache = NSCache()
var customView: UIView!
var labelsArray: [UILabel] = []
var isAnimating = false
var currentColorIndex = 0
var currentLabelIndex = 0
var timer : NSTimer!
var populatingPhotos = false
var currentPage = 0
let PhotoBrowserCellIdentifier = "PhotoBrowserCell"
var dateFormatter = NSDateFormatter()
var nodeIDArray = NSMutableArray()
var timeStampDateString : String!
var cellLoadingIndicator = UIActivityIndicatorView()
var scrollViewDidScrollLoadingIndicator = UIActivityIndicatorView()
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView!.registerClass(PhotoBrowserCollectionViewCell.self, forCellWithReuseIdentifier: PhotoBrowserCellIdentifier)
self.cellLoadingIndicator.backgroundColor = goldenWordsYellow
self.cellLoadingIndicator.hidesWhenStopped = true
if self.revealViewController() != nil {
revealViewControllerIndicator = 1
menuButton.target = self.revealViewController()
menuButton.action = "revealToggle:"
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
self.revealViewController().rearViewRevealWidth = 280
collectionView!.delegate = self
collectionView!.dataSource = self
goldenWordsRefreshControl = UIRefreshControl()
goldenWordsRefreshControl.backgroundColor = goldenWordsYellow
goldenWordsRefreshControl.tintColor = UIColor.whiteColor()
self.collectionView!.addSubview(goldenWordsRefreshControl)
navigationController?.setNavigationBarHidden(false, animated: true)
navigationItem.title = "Pictures"
setupView()
populatePhotos()
self.dateFormatter.dateFormat = "dd/MM/yy"
self.cellLoadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
self.cellLoadingIndicator.color = goldenWordsYellow
self.cellLoadingIndicator.center = (self.collectionView?.center)!
self.collectionView!.addSubview(cellLoadingIndicator)
self.collectionView!.bringSubviewToFront(cellLoadingIndicator)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
if goldenWordsRefreshControl.refreshing {
if !isAnimating {
holdRefreshControl()
}
}
}
func holdRefreshControl() {
timer = NSTimer.scheduledTimerWithTimeInterval(2.0, target: self, selector: "handleRefresh", userInfo: nil, repeats: true)
}
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return (pictureObjects.count) // setting an arbitrary value in case pictureObjects is not getting correctly populated
}
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(PhotoBrowserCellIdentifier, forIndexPath: indexPath) as! PhotoBrowserCollectionViewCell
if let pictureObject = pictureObjects.objectAtIndex(indexPath.row) as? PictureElement {
let title = pictureObject.title ?? "" // if pictureObject.title == nil, then we return an empty string
let timeStampDateObject = NSDate(timeIntervalSince1970: NSTimeInterval(pictureObject.timeStamp))
let timeStampDateString = dateFormatter.stringFromDate(timeStampDateObject)
let author = pictureObject.author ?? ""
let issueNumber = pictureObject.issueNumber ?? ""
let volumeNumber = pictureObject.volumeNumber ?? ""
let nodeID = pictureObject.nodeID ?? 0
let imageURL = pictureObject.imageURL ?? "http://goldenwords.ca/sites/all/themes/custom/gw/logo.png"
cell.request?.cancel()
if let image = self.imageCache.objectForKey(imageURL) as? UIImage {
cell.imageView.image = image
} else {
cell.imageView.image = nil
cell.request = Alamofire.request(.GET, imageURL).responseImage() { response in
if let image = response.result.value {
self.imageCache.setObject(response.result.value!, forKey: imageURL)
if cell.imageView.image == nil {
cell.imageView.image = image
}
}
}
}
}
return cell
}
self.performSegueWithIdentifier("ShowPhoto", sender: self)
}
func setupView() {
navigationController?.setNavigationBarHidden(false, animated: true)
let layout = UICollectionViewFlowLayout()
let itemWidth = (view.bounds.size.width)/3
layout.itemSize = CGSize(width: itemWidth, height: itemWidth)
layout.minimumInteritemSpacing = 1.0
layout.minimumLineSpacing = 1.0
collectionView!.collectionViewLayout = layout
navigationItem.title = "Pictures"
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSizeMake(((self.collectionView?.frame.width)!*0.5)-2, self.collectionView!.frame.height/3)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowPhoto" {
let detailViewController = segue.destinationViewController as! PhotoViewerViewController
let indexPaths = self.collectionView!.indexPathsForSelectedItems()
let indexPath = indexPaths![0] as! NSIndexPath
let item = indexPath.item
}
}
override func scrollViewDidScroll(scrollView: UIScrollView) {
if (scrollView.contentOffset.y + view.frame.size.height > scrollView.contentSize.height * 0.75) {
populatePhotos()
}
}
func populatePhotos() {
if populatingPhotos {
return
}
populatingPhotos = true
self.cellLoadingIndicator.startAnimating()
self.temporaryPictureObjects.removeAllObjects()
Alamofire.request(GWNetworking.Router.Pictures(self.currentPage)).responseJSON() { response in
if let JSON = response.result.value {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0)) {
var nodeIDArray : [Int]
if (JSON .isKindOfClass(NSDictionary)) {
for node in JSON as! Dictionary<String, AnyObject> {
let nodeIDValue = node.0
var lastItem : Int = 0
self.nodeIDArray.addObject(nodeIDValue)
if let pictureElement : PictureElement = PictureElement(title: "Picture", nodeID: 0, timeStamp: 0, imageURL: "http://goldenwords.ca/sites/all/themes/custom/gw/logo.png", author: "Staff", issueNumber: "Issue # error", volumeNumber: "Volume # error") {
pictureElement.title = node.1["title"] as! String
pictureElement.nodeID = Int(nodeIDValue)!
let timeStampString = node.1["revision_timestamp"] as! String
pictureElement.timeStamp = Int(timeStampString)!
if let imageURL = node.1["image_url"] as? String {
pictureElement.imageURL = imageURL
}
if let author = node.1["author"] as? String {
pictureElement.author = author
}
if let issueNumber = node.1["issue_int"] as? String {
pictureElement.issueNumber = issueNumber
}
if let volumeNumber = node.1["volume_int"] as? String {
pictureElement.volumeNumber = volumeNumber
}
if self.pictureObjects.containsObject(pictureElement) {
// do not add the pictureElement to the set of pictures
} else {
lastItem = self.temporaryPictureObjects.count // Using a temporary set to not handle the dataSource set directly (safer).
self.temporaryPictureObjects.addObject(pictureElement)
}
let indexPaths = (lastItem..<self.temporaryPictureObjects.count).map { NSIndexPath(forItem: $0, inSection: 0) }
}
}
let timeStampSortDescriptor = NSSortDescriptor(key: "timeStamp", ascending: false)
self.temporaryPictureObjects.sortUsingDescriptors([timeStampSortDescriptor])
}
dispatch_async(dispatch_get_main_queue()) {
for object in self.temporaryPictureObjects {
self.pictureObjects.addObject(object)
}
self.temporaryPictureObjects.removeAllObjects()
self.collectionView!.reloadData()
self.cellLoadingIndicator.stopAnimating()
self.goldenWordsRefreshControl.endRefreshing()
self.currentPage++
self.populatingPhotos = false
}
}
}
}
}
func handleRefresh() {
goldenWordsRefreshControl.beginRefreshing()
self.pictureObjects.removeAllObjects()
self.temporaryPictureObjects.removeAllObjects()
self.collectionView!.reloadData()
self.currentPage = 0
self.picturesCollectionView.bringSubviewToFront(cellLoadingIndicator)
self.populatingPhotos = false
populatePhotos()
}
}
尝试设置后调用reloadData上UIcollectionview一次。 –