在 Swift 3 中过滤 UICollectionview 上的结果不起作用？答案

【问题标题】：Filtering the results on a UICollectionview in Swift 3 not working?在 Swift 3 中过滤 UICollectionview 上的结果不起作用？
【发布时间】：2017-06-23 09:53:19
【问题描述】：

第一次加载 itemlist 工作正常，但过滤后集合视图没有更新。我添加了一个搜索栏并尝试过滤结果，但 UICollectionview 无法更新视图。

var resultSearchController = UISearchController()
//itemlist
var itemList = [item1, item2, item3, item4,..] 

//configured searchbar

func viewDidLoad() {
      self.resultSearchController = UISearchController(searchResultsController: nil)
      self.resultSearchController.searchResultsUpdater = self
      self.resultSearchController.searchBar.delegate = self
      self.definesPresentationContext = true
      self.resultSearchController.dimsBackgroundDuringPresentation = false
      self.resultSearchController.searchBar.placeholder = "Search for Items"
      self.resultSearchController.searchBar.searchBarStyle = UISearchBarStyle.prominent
      self.resultSearchController.searchBar.sizeToFit()
}

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
      if resultSearchController.isActive {
            return filterSearch.count
      }
      return itemList.count
      }

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
      var item = itemList()
      if resultSearchController.isActive {
            item = filterSearch[indexPath.row]
      } else {
            item = itemList[indexPath.row]
      }
      let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellIdentifier", for: indexPath)
      cell.titleLabel.text = item
      return cell
}

//将项目过滤到filterSearch但集合视图没有根据过滤器更新。

func updateSearchResults(for searchController: UISearchController) {
       filterSearch = itemList.filter { itemList  in
            return temList.name.lowercased().contains(searchText.lowercased())
      }
      self.collectionView?.reloadData()
}

【问题讨论】：

你能在你的代码中提供更多关于“storeList”的代码吗？
通过调试我看到searchcontroller虽然处于活动状态，但并未显示为活动状态。你能告诉我我犯的错误吗？@PhaniSai
您的代码看起来不错，但是您可以在返回“true”时检查“resultSearchController.isActive”
在激活编辑时，resultSearchController.isActive 返回“true”，但在编辑时返回 false。你能解释一下吗？ @PhaniSai
我刚刚更新了答案看看变化

标签： swift3 uicollectionview uisearchcontroller uisearchresultscontroller

【解决方案1】：

检查以下代码中的更改

var resultSearchController = UISearchController()
//itemlist
var itemList = [item1, item2, item3, item4,..] 

//configured searchbar
var issearchactive:Bool = false

func viewDidLoad() {
      self.resultSearchController = UISearchController(searchResultsController: nil)
      self.resultSearchController.searchResultsUpdater = self
      self.resultSearchController.searchBar.delegate = self
      self.definesPresentationContext = true
      self.resultSearchController.dimsBackgroundDuringPresentation = false
      self.resultSearchController.searchBar.placeholder = "Search for Items"
      self.resultSearchController.searchBar.searchBarStyle = UISearchBarStyle.prominent
      self.resultSearchController.searchBar.sizeToFit()
}

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
      if issearchactive {
            return filterSearch.count
      }
      return itemList.count
      }

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
      var item = itemList()
      if issearchactive {
            item = filterSearch[indexPath.row]
      } else {
            item = itemList[indexPath.row]
      }
      let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellIdentifier", for: indexPath)
      cell.titleLabel.text = item
      return cell
}

    func updateSearchResults(searchText:String) {
           filterSearch = itemList.filter { obj  in
                return obj.name.lowercased().contains(searchText.lowercased())
          }
          self.collectionView?.reloadData()
    }


  override func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {

        issearchactive = true
        return true
    }

  override func textFieldDidEndEditing(_ textField: UITextField) {

      updateSearchResults(searchText:textfield.text)

        issearchactive = false

         }

    override func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

  updateSearchResults(searchText:textfield.text)

        return true
    }

【讨论】：