函數內的訪問變量，並將其作爲另一個函數的返回swift

Question

import UIKit 

class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource { 

    var collectionView: UICollectionView? 

    var instanceOfCustomObject: CustomObject = CustomObject() 
    var accessToken: NSString! 
    var userDefaults: NSUserDefaults! 

    var responseDictionary: NSDictionary! 
// var currentResponse: NSArray! 


    // the range represents integer values 0, 1, and 2 
    // the range now represents integer values 6, 7, and 8 

    let colorWheel = ColorWheel() 
// let parse = Parse() 

// var currentResponse: NSArray? 
// struct photoCount { 
// init(responseDictionary: NSDictionary) { 
// 
//  //  var currentResponse = responseDictionary["data"] as NSDictionary 
// 
//  var currentResponse = responseDictionary.valueForKeyPath("data") as NSArray 
//  var photoCount = currentResponse.count as Int 
//  println(photoCount) 
// } 
// } 
    var photoCount: Int! 

// private let api = "d4984c8cfa78689bd066d82bec820fd5" 



    override func viewDidLoad() { 
     super.viewDidLoad() 

     userDefaults = NSUserDefaults.standardUserDefaults() 
     self.accessToken = userDefaults!.objectForKey("accessToken") as NSString 
     println(self.accessToken) 

     //  instanceOfCustomObject.someProperty = "Hello World" 
//  var accessToken : NSString? = NSString(instanceOfCustomObject.accessToken) 
//  println(accessToken) 
//  instanceOfCustomObject.authorize() 
//  instanceOfCustomObject.simpleAuth() 


     // Do any additional setup after loading the view, typically from a nib. 
     let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout() 
//  layout.sectionInset = UIEdgeInsets(top: 20, left: 0, bottom: 0, right: 0) 
     layout.itemSize = CGSize(width: 124, height: 124) 
     layout.minimumInteritemSpacing = 1.0 
     layout.minimumLineSpacing = 1.0 
     collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout) 
     collectionView!.dataSource = self 
     collectionView!.delegate = self 
     collectionView!.registerClass(Cell.self, forCellWithReuseIdentifier: "Cell") 
     collectionView!.backgroundColor = UIColor.whiteColor() 
     self.view.addSubview(collectionView!) 

     getData() 

    } 

    func getData() -> Void { 
     let baseUrl = NSURL(string:"https://api.instagram.com/v1/users/3/media/recent/?access_token=\(self.accessToken)") 

     let forcastUrl = NSURL(string: "", relativeToURL: baseUrl) 

     //  let data = NSData(contentsOfURL: forcastUrl) 
     //  println(data) 
     let sharedSession = NSURLSession.sharedSession() 
     let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(baseUrl, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in 


      //   var urlContents = NSString.stringWithContentsOfURL(location, encoding: NSUTF8StringEncoding, error: nil) 
      //   println(urlContents) 

      let dataObject = NSData(contentsOfURL: baseUrl) 
      //   println(dataObject) 
      if (error == nil) { 
       let responseDictionary: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataObject, options: nil, error: nil) as NSDictionary 

       var currentResponse = responseDictionary.valueForKeyPath("data") as NSArray 

       //    println(currentResponse) 
       //    self.currentResponse = currentResponse as NSArray 
       self.photoCount = currentResponse.count as Int 
       println(self.photoCount) 

       dispatch_async(dispatch_get_main_queue(), {() -> Void in 

        //     self.temperatureLabel.text = "\(currentWeather.temperature)" 
        //     self.iconView.image = currentWeather.icon! 
        //     self.currentTimeLabel.text = "At \(currentWeather.currentTime!) it is" 
        //     self.humidityLabel.text = "\(currentWeather.humidity)" 
        //     self.percipitationLabel.text = "\(currentWeather.precipProbability)" 
        //     self.summeryLabel.text = "\(currentWeather.summary)" 
        // 
        //     self.refreshActivityIndicator.stopAnimating() 
        //     self.refreshActivityIndicator.hidden = true 
        // 
        //     self.refreshButton.hidden = false 
       }) 

      } else { 

       let networkIssueController = UIAlertController(title: "Error", message: "I got 99 problems but a bitch ain't one", preferredStyle: .ActionSheet) 
       let okButton = UIAlertAction(title: "OK", style: .Default, handler: nil) 
       networkIssueController.addAction(okButton) 
       let cancelButton = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil) 
       networkIssueController.addAction(cancelButton) 

       self.presentViewController(networkIssueController, animated: true, completion: nil) 

       dispatch_async(dispatch_get_main_queue(), {() -> Void in 
        //Stop refresh animation 
        //     self.refreshActivityIndicator.stopAnimating() 
        //     self.refreshActivityIndicator.hidden = true 
        //     self.refreshButton.hidden = false 

       }) 

      } 

     }) 

     downloadTask.resume() 

    } 

在getData（）函數中，名爲「currentResponse」的變量檢索一個urls數組。那麼我算陣列和號碼分配給一個名爲「光子計數」

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 


//  var photoCount = parse.photoCount(currentResponse) 
     return photoCount 
    } 

我想用「PHOTOCOUNT」變量來告訴我的集合視圖功能，它應該有多少段具有可變！有20個網址，所以它應該輸出20個方格，但目前的photoCount是零！我是否需要將「photoCount」設置爲全局變量？一直困在這個很長時間，請幫助！

Answer 1

您收藏視圖的大小分配爲無當您的視圖控制器加載並且不會隨時更新，任何地方。您必須異步重新加載您的集合視圖。

在你的getData功能，把這個：

dispatch_async(dispatch_get_main_queue(), { 
    self.photoCount = currentResponse.count as Int 
    self.collectionView.reloadData()   
})