数据解析后重新加载UICollection视图

Question

我正在尝试动态更新一个uicollectionview。我用this amazing tutorial就如何创建一个简单的自选。

它使用项目的静态数组时很好用。我的问题 - 我想要的uicollection填充数据从我的数据库解析成一个新的数组。我不知道如何在解析我的json数据后重新加载uicollection。

使用答案更新的代码：

import UIKit 

class Books: UIViewController, UICollectionViewDelegate { 

    @IBOutlet weak var bookscollection: UICollectionView! 

    var user_id: Int = 0; 

    //------------ init ---------------// 

    override func viewDidLoad() { 
     super.viewDidLoad() 

    } 

    override func viewDidAppear(_ animated: Bool) { 
     showtutorial() 
     getuserid() 
    } 


    //------------ show books ---------------// 

    var booknames = [String]() 
    var bookcolor = [String]() 
    var bookdescription = [String]() 
    var bookid = [Int]() 

    func posttoapi(){ 

     //show loading 
     LoadingOverlay.shared.showOverlay(view: self.view) 

     //send 
     let url:URL = URL(string: "http://www.url.com")! 
     let session = URLSession.shared 
     var request = URLRequest(url: url) 
     request.httpMethod = "POST" 
     request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData 
     let paramString = "user_id=\(user_id)" 
     request.httpBody = paramString.data(using: String.Encoding.utf8) 

     let task = session.dataTask(with: request as URLRequest) {(data, response, error) in 

      //hide loading 
      LoadingOverlay.shared.hideOverlayView() 

      //no response 
      guard let data = data, let _:URLResponse = response, error == nil else { 
       print("response error") 
       return 
      } 

      //response, parse and send to build 
      let json = String(data: data, encoding: String.Encoding.utf8); 
      if let data = json?.data(using: String.Encoding.utf8){ 

       let json = try! JSON(data: data) 

       for item in json["rows"].arrayValue { 

        //push data to arrays 
        self.booknames.append(item["name"].stringValue) 
        self.bookcolor.append(item["color"].stringValue) 
        self.bookdescription.append(item["description"].stringValue) 
        self.bookid.append(item["id"].int!) 

        //reload uicollection 
        DispatchQueue.main.sync(execute: { 
         self. bookscollection.reloadData() 
        }) 


       } 

      } 

     } 

     task.resume() 

    } 




    //------------ collection -------------// 

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

     print("collection view code called") 
     return self.booknames.count 
    } 


    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 
     let cell = bookscollection.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! BooksCell 
     cell.myLabel.text = self.booknames[indexPath.item] 
     cell.backgroundColor = UIColor.cyan // make cell more visible in our example project 
     return cell 
    } 


    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
     print("You selected cell #\(indexPath.item)!") 
    } 



    //------------ end ---------------// 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
    } 


} 

感谢您的帮助！

Answer 1

同样的问题我faced..your有很多图片的URL意味着重装牛逼

dispatch_async(dispatch_get_main_queue(), { 
    self.collectionView.reloadData() 
})