我想在我的应用程序中使用解析并实现搜索功能,并希望使用重载数据对PFObjects进行排序。我的应用程序可以首次执行reloadData(),但它在第一次之后返回“意外地发现零,同时展开可选值”。我已经尝试在mainThread中执行reloadData并删除我的collectionView中的弱引用,但它仍然不起作用。我附上了我的代码。先谢谢你!UICollectionView不重装数据
@IBOutlet var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
loadCollectionViewData()
}
//This method is also conducted when the user taps search button
func loadCollectionViewData(){
let ud = NSUserDefaults.standardUserDefaults()
var query = PFQuery(className: "Posts")
if ud.objectForKey("searchKeyFromVCKey") != nil{
//This is keyword the user puts in
var searchKey = ud.objectForKey("searchKeyFromVCKey") as! String
println("searchKey \(searchKey)")
if searchKey != "" {
//If a user is searching something...
query.whereKey("searchTag", containsString: searchKey.lowercaseString)
}}
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
postObject.removeAll(keepCapacity: false)
if let object = objects as? [PFObject] {
postObject = object
}
self.collectionView.reloadData() //This works the first time when I conduct loadCollectionViewData() in ViewDidLoad
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
}
ud.removeObjectForKey("searchKeyFromVCKey")
}
哪个引用意外地为零? –
@AaronBrager我不知道如何找到哪个引用是意外的零。通过此代码,self.collectionView.reloadData()以绿色高亮显示,并发生错误。 – Emily
将'postObject = object'改为'postObject = object!' – DDPWNAGE