//
// ViewController.swift
// Fashun
//
// Created by Alex Macleod on 20/10/14.
// Copyright (c) 2014 Alex Macleod. All rights reserved.
//
import UIKit
class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
var collectionView: UICollectionView?
var instanceOfCustomObject: CustomObject = CustomObject()
var accessToken: NSString!
var userDefaults: NSUserDefaults!
let colorWheel = ColorWheel()
var photoCount: Int! = 0
let photos = NSMutableArray()
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()
// 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/7522782/media/recent/?access_token=\(self.accessToken)")
// let forcastUrl = NSURL(string: "37.8267,-122.423", 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!)
if (error == nil) {
let responseDictionary: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataObject!, options: nil, error: nil) as NSDictionary
// println(responseDictionary)
var currentResponse = responseDictionary.valueForKeyPath("data.images.standard_resolution.url") as NSArray
dispatch_async(dispatch_get_main_queue(), { () -> Void in
// for url in currentResponse {
// var urlStrings: NSString = url as NSString
//
// var images = UIImage(data: NSData(contentsOfURL: NSURL(string:urlStrings)!)!)
//
// }
for url in currentResponse {
var urls: NSString = url as NSString
// println(images)
var photoUrls = NSURL(string: urls)
var err: NSError?
var imageData :NSData = NSData(contentsOfURL: photoUrls!,options: NSDataReadingOptions.DataReadingMappedIfSafe, error: &err)!
self.photos.addObject(UIImage(data:imageData)!)
println(self.photos)
}
self.photoCount = currentResponse.count as Int
self.collectionView?.reloadData()
})
} else {
let networkIssueController = UIAlertController(title: "Error", message: "Something went wrong get a better phone you pleb!", 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
})
}
})
downloadTask.resume()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return photoCount
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as Cell
// println(photos)
// cell.textLabel.text = "Text"
cell.imageView.image = photos.objectAtIndex(indexPath.row) as? UIImage
// cell.photo = self.photos[indexPath.row] as? NSDictionary
cell.imageView.backgroundColor = colorWheel.randomColor()
return cell
}
}
正如您所看到的，我有一个NSURLDownload会话，可以从用户＆＃34; 7522782＆＃34;下载Instagram上的信息。我解析数据并计算＆＃34; currentResponse＆＃34;数组，以获取我的集合视图中需要的单元格数。然后我将信息转换网址解析为UIimages并将它们放入单元格中。
如何为多个用户执行此操作。我想展示20多位用户的照片 请记住，我需要总结所有用户的照片总数，以告诉我的收藏品查看要制作的细胞数量。
提前致谢。
答案 0 :(得分：0)
这是我现在想的一种方式......
首先修复您使用调度的方式...... A Good Answer about Dispatch Queues
//Might run into an issue that if you insert more heavy logic here your UI will get stuck until processing ends.
dispatch_async(dispatch_get_main_queue(), { () -> Void in }
因此，使用dispatch_get_global_queue代替背景线程，然后在想要运行将在Background闭包（Block）内更新UI的代码时调用dispatch_get_main_queue。
//Correct way to use it to do Background work.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), {
//async code the callings to the NSUrlSession any other logic
dispatch_async(dispatch_get_main_queue(), { () -> Void in
//Do UI Updates Code.
}
}
现在针对您的具体情况。您正确处理用户获取该用户的照片的所有网址，因此现在添加这样的内容以处理同一屏幕的多个用户。问题是需要花费很长时间才能下载20多个用户的照片，但由于你正在进行异步操作，屏幕不会卡住。
照片的矩阵，数组阵列;主数组中的每个数组都是每个用户的照片集。
var photoUserMatrix = [NSMutableArray]() //using Swift array and NSMutableArray
或者使用它，因为你更倾向于使用NSMutableArrays
var photoUserMatrix = NSMutableArray()
photoUserMatrix.addObject(NSMutableArray())//Each Photo Set per user is a new array.
Matrix的问题是在执行时间内找到的东西是O（N ^ 2）。
无论如何，现在您可以拥有X个用户，您的代码将处理它。通过使用这段代码。
//Use this pseudo code to start downloading the multiple pictures for the users.
for i in 0...countOfUsers{
//Create the array of Photos for this user.
var newPhotoSet = NSMutableArray()
//Now use your code that downloads the photos with
//the Urls given for that users photos. with another loop on the Count of Urls/Photos
for pos in 0...countOfUrls{
//Download the Image with NSUrlSession
//and add the photo to the new Array in the CompletionHandler
newPhotoSet.AddObject(newImageDownloaded);
}
photoUserMatrix.addObject(newPhotoSet)
}
显示CollectionViewCells的代码。
for photoSet in photoUserMatrix as (NSMutableArray) {
var count:Int = photoSet.count
for i in 0...count{
//use algorithm to display downloaded pictures in CollectionView.
//If any image is nil do not display that image.
//Same Code can be used to do the sum of all photos in each array.
}
}
请记住，这不是最佳解决方案。此外，应用程序的设计没有帮助，在同一个屏幕上为20多个用户执行加载图像是一个问题，除非图像真的很小，否则你将在那里运行。
另外我建议你将这个工作逻辑代码添加到一个方法中，该方法将为需要下载图像的每个用户调用Dispatch_get_global_queue，使其更加并发。
PS：如果你遇到任何问题，请告诉我，我很乐意帮助你。