Question

我在下面有一些代码。我有一个来自SwiftyJSON的JSON对象，我想过滤它。很自然地，我想：让我们过滤它并使用过滤后的数据实例化一个新数组。

import UIKit
import SwiftyJSON
import Alamofire

class SchoolSelectViewController: UITableViewController, UISearchResultsUpdating, UISearchBarDelegate {
  let url = "https://mijn.magister.net/api/schools?filter=%%%".stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())
  var json: JSON = []
  var filteredJson: JSON = []
  var resultSearchController = UISearchController()

  override func viewDidLoad() {
    super.viewDidLoad()

    Alamofire.request(.GET, self.url!).validate().responseJSON {
      response in
      switch response.result {
      case .Success:
        if let value = response.result.value {
          self.json = JSON(value)
        }

        self.resultSearchController = UISearchController(searchResultsController: nil)
        self.resultSearchController.searchResultsUpdater = self
        self.resultSearchController.searchBar.delegate = self
        self.resultSearchController.searchBar.sizeToFit()

        self.tableView.tableHeaderView = self.resultSearchController.searchBar
        self.definesPresentationContext = true
        self.tableView.reloadData()
        break
      case .Failure: break
      }
    }

    self.navigationController?.navigationBarHidden = true
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    print("Called tableView cellForRowAtIndexPath")
    let cell = tableView.dequeueReusableCellWithIdentifier("schoolSelectCell")! as UITableViewCell
    let cellTitle = json[indexPath.row]["Name"]
    let cellDetailTitle = json[indexPath.row]["Url"]

    cell.accessoryType = UITableViewCellAccessoryType.DisclosureIndicator
    cell.textLabel?.text = cellTitle.string
    cell.detailTextLabel?.text = cellDetailTitle.string

    return cell
  }

  override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    if (self.resultSearchController.active) {
      return self.filteredJson.count
    } else {
      return self.json.count
    }
  }

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

  func updateSearchResultsForSearchController(searchController: UISearchController) {
    let searchString = self.resultSearchController.searchBar.text
  }

  func filterContentForTextSearch(searchText: String) {
    self.filteredJson = self.json[0]["Name"].arrayValue.filter({
      (school: JSON) -> Bool in
    })
  }

}

但我结束了接收此错误：Cannot convert value of type 'JSON -> Bool' to expected argument type '(Element) -> Bool'

我该如何解决这个问题？

Answer 1

你应该过滤一个数组。

使用以下内容：

self.filteredJson = self.json.arrayValue.filter({
     (school: JSON) -> Bool in
      // Do something.
})

如果上述代码不起作用，请检查JSON的类型。

iOS数据过滤错误

1 个答案: