我在loadinbackground上遇到了问题。我收到一个错误，说不能调用没有参数的loadinBackground。
以下是我的代码，我已经在互联网上查看，并且不知道为什么这不起作用。
import UIKit
import Parse
import ParseUI
class DetailViewController: UIViewController, UINavigationControllerDelegate {
// Container to store the view table selected object
var currentObject : PFObject?
// Some text fields
@IBOutlet weak var topsLabel: UITextField!
@IBOutlet weak var topsImageView: PFImageView!
var updateObject : PFObject?
// The save button
@IBAction func saveButton(sender: AnyObject) {
// Use the sent country object or create a new country PFObject
if let updateObjectTest = currentObject as PFObject? {
updateObject = currentObject! as PFObject
} else {
updateObject = PFObject(className:"Tops")
}
// Update the object
if let updateObject = updateObject {
updateObject["topsLabel"] = topsLabel.text
// Create a string of text that is used by search capabilites
var searchText = (topsLabel.text).lowercaseString
updateObject["searchText"] = searchText
// Update the record ACL such that the new record is only visible to the current user
updateObject.ACL = PFACL(user: PFUser.currentUser()!)
// Save the data back to the server in a background task
updateObject.save()
}
// Return to table view
self.navigationController?.popViewControllerAnimated(true)
}
override func viewDidLoad() {
super.viewDidLoad()
// Unwrap the current object object
if let object = currentObject {
if let value = object["topsLabel"] as? String {
topsLabel.text = value
// Display standard question image
var initialThumbnail = UIImage(named: "question")
topsImageView.image = initialThumbnail
// Replace question image if an image exists on the parse platform
if let thumbnail = object["topsImageView"] as? PFFile {
topsImageView.file = thumbnail
topsImageView.loadInBackground()
}
}
}
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}
Tops View
import UIKit
import Parse
var tops = [PFObject]()
class TopsViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UISearchBarDelegate {
// Connection to the search bar
@IBOutlet weak var searchBar: UISearchBar!
// Connection to the collection view
@IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
// Wire up search bar delegate so that we can react to button selections
searchBar.delegate = self
// Resize size of collection view items in grid so that we achieve 3 boxes across
let cellWidth = ((UIScreen.mainScreen().bounds.width) - 32 - 30 ) / 3
let cellLayout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
cellLayout.itemSize = CGSize(width: cellWidth, height: cellWidth)
}
/*
==========================================================================================
Ensure data within the collection view is updated when ever it is displayed
==========================================================================================
*/
// Load data into the collectionView when the view appears
override func viewDidAppear(animated: Bool) {
loadCollectionViewData()
}
/*
==========================================================================================
Fetch data from the Parse platform
==========================================================================================
*/
func loadCollectionViewData() {
// Build a parse query object
var query = PFQuery(className:"Tops")
// Check to see if there is a search term
if searchBar.text != "" {
query.whereKey("uploader", containsString: searchBar.text.lowercaseString)
}
// Fetch data from the parse platform
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
// The find succeeded now rocess the found objects into the countries array
if error == nil {
// Clear existing country data
tops.removeAll(keepCapacity: true)
// Add country objects to our array
if let objects = objects as? [PFObject] {
tops = Array(objects.generate())
}
// reload our data into the collection view
self.collectionView.reloadData()
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
}
}
/*
==========================================================================================
UICollectionView protocol required methods
==========================================================================================
*/
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return tops.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("mySingleCell", forIndexPath: indexPath) as! SingleRowCell
// Display the country name
if let value = tops[indexPath.row]["topsLabel"] as? String {
cell.topsLabel.text = value
}
// Display "initial" flag image
var initialThumbnail = UIImage(named: "question")
cell.topsImageView.image = initialThumbnail
// Fetch final flag image - if it exists
if let value = tops[indexPath.row]["tops"] as? PFFile {
let finalImage = tops[indexPath.row]["tops"] as? PFFile
finalImage!.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
if let imageData = imageData {
cell.topsImageView.image = UIImage(data:imageData)
}
}
}
}
return cell
}
/*
==========================================================================================
Segue methods
==========================================================================================
*/
// Process collectionView cell selection
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let currentObject = tops[indexPath.row]
performSegueWithIdentifier("CollectionViewToDetailView", sender: currentObject)
}
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// If a cell has been selected within the colleciton view - set currentObjact to selected
var currentObject : PFObject?
if let country = sender as? PFObject{
currentObject = sender as? PFObject
} else {
// No cell selected in collectionView - must be a new country record being created
currentObject = PFObject(className:"Tops")
}
// Get a handle on the next story board controller and set the currentObject ready for the viewDidLoad method
var detailScene = segue.destinationViewController as! DetailViewController
detailScene.currentObject = (currentObject)
}
/*
==========================================================================================
Process Search Bar interaction
==========================================================================================
*/
func searchBarTextDidEndEditing(searchBar: UISearchBar) {
// Dismiss the keyboard
searchBar.resignFirstResponder()
// Reload of table data
self.loadCollectionViewData()
}
func searchBarSearchButtonClicked(searchBar: UISearchBar) {
// Dismiss the keyboard
searchBar.resignFirstResponder()
// Reload of table data
self.loadCollectionViewData()
}
func searchBarCancelButtonClicked(searchBar: UISearchBar) {
// Clear any search criteria
searchBar.text = ""
// Dismiss the keyboard
searchBar.resignFirstResponder()
// Reload of table data
self.loadCollectionViewData()
}
/*
==========================================================================================
Process memory issues
To be completed
==========================================================================================
*/
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
上传图片
@IBAction func uploadButton(sender: AnyObject) {
var imageText = uploadMessage.text
if uploadPreviewImageView.image == nil {
//image is not included alert user
println("Image not uploaded")
}else {
var posts = PFObject(className: "Tops")
posts["imageText"] = imageText
posts["uploader"] = PFUser.currentUser()
posts.saveInBackgroundWithBlock({
(success: Bool, error: NSError?) -> Void in
if error == nil {
var imageData = UIImagePNGRepresentation(self.uploadPreviewImageView.image)
var parseImageFile = PFFile(name: "uploaded_image.png", data: imageData)
posts["imageFile"] = parseImageFile
posts.saveInBackgroundWithBlock({
(success: Bool, error: NSError?) -> Void in
if error == nil {
println("finished")
self.performSegueWithIdentifier("goHomeFromUpload", sender: self)
}else {
println(error)
}
})
}else {
println(error)
}