集合视图单元格刷新未发生

Question

当视图加载时，我将通过 API 调用填充数据并将其显示到单元格中：

override func viewDidLoad() {
    super.viewDidLoad()
    parseData(urll: url)
}

当我使用搜索栏进行搜索时，我使用以下代码填充一组新的项目：

func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {

    let keywords = searchBar.text
    let finalKey =  keywords?.replacingOccurrences(of: " ", with: "+")
    let finalurl = "https://api.giphy.com/v1/gifs/search?api_key=0d4f9877de6d4927943adf5a0d20e8a0&q=\(finalKey!)&limit=25&offset=0&rating=G&lang=en"
    parseData(urll: finalurl)
          self.view.endEditing(true)
}

但是当它加载新项目时，旧项目不会被删除，我尝试使用重新加载数据，但它不起作用。

我在

parseData()

功能中有重新加载数据的功能。

parsedata()

代码：

 func parseData(urll : String) {
    var request = URLRequest(url: URL(string: urll)!)
    request.httpMethod = "GET"
    let config = URLSessionConfiguration.default
    let session = URLSession(configuration: config, delegate: nil, delegateQueue: .main)
    let task = session.dataTask(with: request) { (data, response, error) in
        if error != nil {
            print(error!)
        }
        else {
            do {
                let fetchedData = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! NSDictionary
                if  let gifArray = fetchedData.value(forKey: "data") as? NSArray {
                    if  let gifarrayImg = gifArray.value(forKey: "images") as? NSArray {
                        if let gifarrayImgFixedWdth = gifarrayImg.value(forKey: "fixed_width") as? NSArray {
                            for gif in gifarrayImgFixedWdth {
                                if let gifDict = gif as? NSDictionary {
                                    if let imgURL = gifDict.value(forKey: "url") {
                                        print(imgURL)
                                        self.imgUrlArray.append(imgURL as! String)
                                    }
                                    if let imgHeight = gifDict.value(forKey: "height") {
                                        self.height.append(imgHeight as! String)
                                        print(imgHeight)
                                    }
                                    DispatchQueue.main.async {
                                        self.collectionView.reloadData()
                                    }
                                }
                            }
                        }
                    }
                }
            }
            catch {
                print("Error2")
            }
        }
    }
    task.resume()
}

收集视图数据源

 func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return imgUrlArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as? CollectionViewCell
    cell?.layer.shouldRasterize = true
    cell?.layer.rasterizationScale = UIScreen.main.scale

    let resource = ImageResource(downloadURL: URL(string : imgUrlArray[indexPath.row])!, cacheKey: imgUrlArray[indexPath.row])
    cell?.imgview.kf.setImage(with: resource)
    

    return cell!
}

Answer 1

旧项目不会被删除，因为您将搜索中的图像 URL 附加到现有 imageUrlArray 属性。因此，您可以在发出搜索请求之前删除该数组中的所有项目。只需将此行添加到

parsedata()

函数的顶部即可：

self.imageUrlArray.removeAll(keepingCapacity: false)