出于某种原因，我无法弄清楚我做错了什么：
我正在尝试在我的Parse数据库中查询URL，将它们放入一个名为facebookPics的数组中。后来我想在我的cellForRowAtIndexPath中查看，
if facebookPics.count < indexPath.row
然后在我的CollectionViewCells中加载数据。 =＆GT;我每次都有6个。
代码：
override func viewWillAppear(animated: Bool) {
let infoQuery = PFUser.query()
infoQuery?.whereKey("objectId", equalTo: objectID!)
infoQuery?.findObjectsInBackgroundWithBlock({ (results, error) -> Void in
if error != nil{
let userMessage = error!.localizedDescription
let myAlert = UIAlertController(title: "Alert", message: userMessage, preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil)
myAlert.addAction(okAction)
self.presentViewController(myAlert, animated: true, completion: nil)
return
}
else if results != nil{
for result in results! {
let imageFile = result["firstImage"] as! PFFile
// Image muss ja erstmal gedownloaded werden.
imageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error != nil {
let userMessage = error!.localizedDescription
let myAlert = UIAlertController(title: "Alert", message: userMessage, preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil)
myAlert.addAction(okAction)
self.presentViewController(myAlert, animated: true, completion: nil)
return
} else {
if let data = imageData {
self.miniImage.image = UIImage(data: data)
}
}
}
// Jetzt der firstname, birthday und abouttext
var profilText = result["first_name"] as! String
self.nameAgeLabel.text = profilText
if let geburtstag = result["birthday"] as? String {
let calendar = NSCalendar.currentCalendar()
let currentDate = NSDate()
let birthdayFormatter = NSDateFormatter()
birthdayFormatter.dateFormat = "MM/DD/YYYY"
let birthday = birthdayFormatter.dateFromString(geburtstag)
let ageComponents = calendar.components(.Year,
fromDate: birthday!,
toDate: currentDate,
options: [])
let age = ageComponents.year
profilText += ", " + String(age)
self.nameAgeLabel.text = profilText
}
if let hashtags = result["hashtags"] as? String {
self.hashtagText.text = hashtags
}
if let images = result["images"] as? [String] {
for image in images {
let nsURL = NSURL(string: image)
var urls:[NSURL] = [NSURL]()
urls.append(nsURL!)
self.facebookPics = urls
}
print(self.facebookPics)
}
}
self.mainCollectionView.reloadData()
}
})
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let image : UIImage = UIImage(named: "Überschrift.png")!
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 80, height: 30))
imageView.contentMode = .ScaleAspectFit
imageView.image = image
self.navigationItem.titleView = imageView
// Navigation Controller Top soll Durchsichtig sein
self.navigationController?.navigationBar.opaque = true
miniImage.layer.borderWidth = 0.5
miniImage.layer.masksToBounds = false
miniImage.layer.borderColor = UIColor.darkGrayColor().CGColor
miniImage.layer.cornerRadius = miniImage.frame.width/2
miniImage.clipsToBounds = true
hashtagText.layer.borderWidth = 1.5
hashtagText.layer.borderColor = UIColor.darkTextColor().CGColor
hashtagText.layer.cornerRadius = 7
// Suche starten um folgende Infos zu bekommen [Profilbild, firstname, abouttext, andere Bilder adressen.]
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// Alle images.count => returnen! max 6
return 6
}
//FEHLERHAFTE FUNKTION
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let collectionCell:SettingsCollectionViewCell = collectionView.dequeueReusableCellWithReuseIdentifier("collectionCell", forIndexPath: indexPath) as! SettingsCollectionViewCell
collectionView.backgroundColor = UIColor.whiteColor()
collectionCell.backgroundColor = UIColor.whiteColor()
collectionCell.frame.size.width = 80
collectionCell.frame.size.height = 80
collectionCell.layer.borderWidth = 1
collectionCell.layer.borderColor = UIColor.darkGrayColor().CGColor
collectionCell.layer.cornerRadius = collectionCell.frame.size.width/2
if facebookPics.count < indexPath.row{
if let data = NSData(contentsOfURL: facebookPics[indexPath.row]) {
let image = UIImage(data: data)
collectionCell.collectionViewImage.image = image
}
}
else {
// Clear out the image on a recycled cell
collectionCell.collectionViewImage = nil
}
let cellImage = collectionCell.collectionViewImage
if cellImage == nil {
self.counter = 1
print("empty")
collectionCell.collectionViewButton.center.x = 40
collectionCell.collectionViewButton.center.y = 40
collectionCell.collectionViewButton.setImage(UIImage(named: "check.png"), forState: UIControlState.Normal)
}
else {
self.counter = 0
print("hello")
collectionCell.collectionViewButton.center.x = 60
collectionCell.collectionViewButton.center.y = 60
collectionCell.collectionViewButton.setImage(UIImage(named: "close-o.png"), forState: UIControlState.Normal)
collectionCell.collectionViewButton.tintColor = UIColor.redColor()
}
return collectionCell
}
答案 0 :(得分：1)
您必须反转if条件。
如果您有0张图片，那么您当前的代码会进入if块，并尝试显示第3张，因为0＆lt; 3评估为真。这与你想要的完全相反。更常见的是，当前且仅当索引完全超出范围时，您才会输入真分支。
正确的检查是：
if indexPath.row < facebookPics.count {
// logic
}
答案 1 :(得分：0)
不要问我为什么，但这终于有效。
Backbone.history.navigate(this.model.get('user').url + '/' + this.model.id, {trigger: false, replace: true});