Swift/iOS 8：搜索欄提高致命錯誤：意外地發現零，同時展開一個可選值

Question

以下this教程，我剛剛添加到我的表視圖控制器的「搜索欄和搜索顯示控制器」。 正如可以從下面的截圖中看到，該表和搜索欄被正確地加載：通過使用「小區」作爲小區重用標識符

。 不管怎麼說，有兩個問題：

1）當搜索欄被竊聽它只是即使它仍然接受了導航欄下消失文本

2）儘快尋找我開始輸入的東西在搜索欄中（即使它是「隱藏的」），則會引發標題中提到的異常。

這裏是我的代碼中使用/ *** /是異常提高，其中線：

import UIKit 

class AllTasksViewController: UITableViewController, UISearchBarDelegate, UISearchDisplayDelegate { 

    var allTasks = [Task]() 
    var taskService = TaskService() 
    var organizedTasks = TaskMenuItems() 
    var filteredTasks = [Task]() 

    override func viewWillAppear(animated: Bool) { 
     self.tabBarController?.navigationItem.setHidesBackButton(true, animated: true) 
     self.tabBarController?.navigationItem.rightBarButtonItem = self.editButtonItem() 
     if (LoggedUser.isLogged) { 
      self.navigationItem.setHidesBackButton(false, animated: true) 
      self.taskService.requestAllTasks { 
       (response) in 
       self.allTasks = self.taskService.loadTasks(response) as! [Task] 
       self.organizedTasks.organize(self.allTasks) 
       /*println(self.organizedTasks.items["Aperti"]?.count) 
       println(self.organizedTasks.items["Chiusi"]?.count) 
       println(self.organizedTasks.items["Scaduti"]?.count) 
       println(self.organizedTasks.items["Sospesi"]?.count)*/ 
       dispatch_async(dispatch_get_main_queue()) { 
        self.tableView.reloadData() 
       } 
      } 
     } 
    } 

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

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


    /* Number of sections */ 
    override func numberOfSectionsInTableView(tableView: UITableView) -> Int { 
     return self.organizedTasks.sections.count 
    } 

    /* Number of rows for each section */ 
    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 

     if tableView == self.searchDisplayController!.searchResultsTableView { 
      return self.filteredTasks.count 
     } 

     switch section { 
      case 0: 
       return self.organizedTasks.items["Aperti"]!.count 
      case 1: 
       return self.organizedTasks.items["Chiusi"]!.count 
      case 2: 
       return self.organizedTasks.items["Scaduti"]!.count 
      case 3: 
       return self.organizedTasks.items["Sospesi"]!.count 
      default: 
       return -1 
      } 


    } 


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

      l? 
      var selectedStatus:String 
      let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! UITableViewCell /***/ 

      var task:Task 

      if tableView == self.searchDisplayController!.searchResultsTableView { 
       task = filteredTasks[indexPath.row] 
       cell.textLabel?.text = task.titolo 
       cell.detailTextLabel?.textColor = Settings.decideColor(task.priorita) 
       cell.detailTextLabel?.text = task.priorita 
       return cell 
      } 

      switch indexPath.section { 
      case 0: 
       /*let cell = tableView.dequeueReusableCellWithIdentifier("OpenTasks", 
       forIndexPath: indexPath) as! UITableViewCell*/ 
       selectedStatus = "Aperti" 
       break 
      case 1: 
      /*let cell = tableView.dequeueReusableCellWithIdentifier("ClosedTasks", 
       forIndexPath: indexPath) as! UITableViewCell*/ 
       selectedStatus = "Chiusi" 
       break 
      case 2: 
       /*let cell = tableView.dequeueReusableCellWithIdentifier("ExpiredTasks", 
       forIndexPath: indexPath) as! UITableViewCell*/ 
       selectedStatus = "Scaduti" 
       break 
      case 3: 
       /*let cell = tableView.dequeueReusableCellWithIdentifier("SuspendedTasks", 
        forIndexPath: indexPath) as! UITableViewCell*/ 
      selectedStatus = "Sospesi" 
       break 
      default: 
       /*let cell = tableView.dequeueReusableCellWithIdentifier("", 
       forIndexPath: indexPath) as! UITableViewCell*/ 
       selectedStatus = "" 
       break 

      } 

      task = self.organizedTasks.items[selectedStatus]![indexPath.row] 
      cell.textLabel?.text = task.titolo 
      cell.detailTextLabel?.textColor = Settings.decideColor(task.priorita) 
      cell.detailTextLabel?.text = task.priorita 
      return cell 

    } 

    override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? { 
     switch (section) { 
     case 0: 
      let count = self.organizedTasks.items["Aperti"]!.count 
      return "Aperti (\(count))" 
     case 1: 
      let count = self.organizedTasks.items["Chiusi"]!.count 
      return "Chiusi (\(count))" 
     case 2: 
      let count = self.organizedTasks.items["Scaduti"]!.count 
      return "Scaduti (\(count))" 
     case 3: 
      let count = self.organizedTasks.items["Sospesi"]!.count 
      return "Sospesi (\(count))" 
     default: 
      return "" 
     } 
    } 

    func filterContentForSearchText(searchText: String, scope:String="All") { 
     // Filter the array using the filter method 
     self.filteredTasks = self.allTasks.filter({(task: Task) -> Bool in 
      let categoryMatch = (scope == "All") || (task.priorita == scope) 
      let stringMatch = task.titolo.rangeOfString(searchText) 
      return categoryMatch && (stringMatch != nil) 
     }) 
    } 

    func searchDisplayController(controller: UISearchDisplayController, shouldReloadTableForSearchString searchString: String!) -> Bool { 
     self.filterContentForSearchText(searchString) 
     return true 
    } 

    func searchDisplayController(controller: UISearchDisplayController, shouldReloadTableForSearchScope searchOption: Int) -> Bool { 
     self.filterContentForSearchText(self.searchDisplayController!.searchBar.text) 
     return true 
    } 


    // In a storyboard-based application, you will often want to do a little preparation before navigation 
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)  { 
     // Get the new view controller using [segue destinationViewController]. 
     // Pass the selected object to the new view controller. 
    } 



} 

我不知道爲什麼這兩個事情發生。看起來它不能用「Cell」標識符創建另一個單元格，但這很奇怪，因爲當表格被加載時（不使用搜索欄）一切正常，因此標識符Cell被註冊。 拜託，你能幫忙嗎？

Answer 1

嘗試下面的代碼，你必須配置你的搜索顯示控制器或viewDidLoad：

self.searchDisplayController.searchResultsTableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Cell")

此外，使用tableView. dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)

值得一提的是，UISearchDisplayController在iOS 8的，使用已過時代替UISearchController。