ios - 在 UITableView 中实现 UISearchController 以过滤 User 对象数组

Question

在 IOS 应用程序(swift 1.2、Xcode 6.3)上工作时，我正在尝试实现一个搜索栏，以便能够过滤和查找用户对象。但不幸的是，最后一个使用谓词过滤数组的方法 updateSearchResultsForSearchController 抛出了异常:

    2015-07-28 19:19:46.843 app.ios[34471:1158655] 
*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
 reason: 
'Can't use in/contains operator with collection app_ios.User (not a collection)

最后一个方法中 println(self.users) 的输出是:

[app_ios.User, app_ios.User, app_ios.User, app_ios.User, 
app_ios.User, app_ios.User, app_ios.User, app_ios.User, 
app_ios.User, app_ios.User...]

管理 UserViewController 的代码是

import Foundation
import UIKit

class UsersViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

  @IBOutlet var tableview:UITableView!

  let apiClient = ApiClient()

  var users: [User]!

  var searchArray:[AnyObject] = [AnyObject](){
    didSet  {
      self.tableview.reloadData()
    }
  }

  var usersSearchController = UISearchController()

  override func viewDidLoad() {
    super.viewDidLoad()

    self.usersSearchController = ({
      // Two setups provided below:

      // Setup One: This setup present the results in the current view.
      let controller = UISearchController(searchResultsController: nil)
      controller.searchResultsUpdater = self
      controller.hidesNavigationBarDuringPresentation = false
      controller.dimsBackgroundDuringPresentation = false
      controller.searchBar.searchBarStyle = .Minimal
      controller.searchBar.sizeToFit()
      self.tableview.tableHeaderView = controller.searchBar

      return controller
    })()
  }

  override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    println("UsersController viewWillAppear")

    apiClient.usersService.getList() { users, error in
      if users != nil {
        self.users = users
        self.tableview?.reloadData()
      } else {
        println("error: \(error)")
      }
    }
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }

  func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    if ( self.usersSearchController.active){
      return self.searchArray.count ?? 0

    } else {
      return self.users?.count ?? 0

    }
  }

  func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    var cell = tableView.dequeueReusableCellWithIdentifier("userObjectCell") as! UserTableViewCell

    if (self.usersSearchController.active){
      cell.userObject = self.searchArray[indexPath.row] as? User
      return cell

    } else {
      cell.userObject = self.users?[indexPath.row]

      return cell
    }
  }

}

extension UsersViewController: UITableViewDelegate
{
  func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
  {
    tableView.deselectRowAtIndexPath(indexPath, animated: true)
  }
}

extension UsersViewController: UISearchResultsUpdating
{
  func updateSearchResultsForSearchController(searchController: UISearchController)
  {
    self.searchArray.removeAll(keepCapacity: false)

    let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text)
    println(self.users)
    let array = (self.users as NSArray).filteredArrayUsingPredicate(searchPredicate)
    self.searchArray = array
  }
}

Answer 1

感觉你没有设置搜索 Controller 的delegate和datasource给VC。