如何快速在CollectionView中快速加载JSON图像URL

Question

我具有带有图像和标签的集合视图。我能够在集合视图中非常缓慢地加载图像和标签值，这意味着集合视图需要花费大量时间来下载json img url。.但是我需要从json到集合的下载速度更快视图...而且我并没有很快获得10张图像的图像..我不知道为什么会这样发生..任何人都可以帮助我以更快的速度下载集合视图中的json img url。

这是我的代码：

 import UIKit
struct JsonData {
var iconHome: String?
var typeName: String?
init(icon: String, tpe: String) {
    self.iconHome = icon
    self.typeName = tpe
}
}

class HomeViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UITextFieldDelegate {

@IBOutlet weak var collectionView: UICollectionView!

var itemsArray = [JsonData]()
var idArray = [Int]()
var homSe = [JsonDataHome]()
override func viewDidLoad() {
    super.viewDidLoad()

    homeServiceCall()
    //Do any additional setup after loading the view.
    collectionView.delegate = self
    collectionView.dataSource = self
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return itemsArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! HomeCollectionViewCell

    let aData = itemsArray[indexPath.row]
    cell.paymentLabel.text = aData.typeName

    if let url = NSURL(string: aData.iconHome ?? "") {
        if let data = NSData(contentsOf: url as URL) {
            cell.paymentImage.image = UIImage(data: data as Data)
        }
    }
    return cell
}

//MARK:- Service-call
func homeServiceCall(){

    let urlStr = "https://dev.com/webservices"
    let url = URL(string: urlStr)
    URLSession.shared.dataTask(with: url!, completionHandler: {(data, response, error) in

        guard let respData = data else {
            return
        }
        guard error == nil else {
            print("error")
            return
        }
        do{
            let jsonObj = try JSONSerialization.jsonObject(with: respData, options: .allowFragments) as! [String: Any]
            //print("the home json is \(jsonObj)")
            let financerArray = jsonObj["financer"] as! [[String: Any]]
            for financer in financerArray {

                let id = financer["id"] as? Int
                let pic = financer["icon"] as? String
                let typeName = financer["tpe"] as! String
                self.idArray.append(id ?? 1)

                self.itemsArray.append(JsonData(icon: pic ?? "", tpe: typeName))
            }
            DispatchQueue.main.async {
                self.collectionView.reloadData()
            }
        }
        catch {
            print("catch error")
        }
    }).resume()
}
}

这里我需要在集合视图中快速下载json图像。

Answer 1

第一