我尝试在我的ViewController中实现一个UISearchController。但是,当我尝试从按钮打开Controller时,它会使应用程序崩溃,并且Xcode没有给出错误。我使用Backendless来存储用户并检索它们。我想搜索它们。 这是我的代码。我不知道自己做错了什么:/我真的很感激帮助。
import UIKit
protocol ChooseUserDelegate {
func chreatChatroom(withUser: BackendlessUser)
}
class ChooseUserViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchResultsUpdating {
@IBOutlet weak var tableView: UITableView!
var delegate: ChooseUserDelegate!
var users: [BackendlessUser] = []
var filteredUsers = [BackendlessUser]()
var resultSearchController: UISearchController!
override func viewDidLoad() {
super.viewDidLoad()
loadUsers()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//MARK: UITableviewDataSorce
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func updateSearchResultsForSearchController(searchController: UISearchController) {
self.filteredUsers.removeAll(keepCapacity: false)
let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text!); let array = (self.users as NSArray).filteredArrayUsingPredicate(searchPredicate)
self.filteredUsers = array as! [BackendlessUser]
self.tableView.reloadData()
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if resultSearchController.active
{
return self.filteredUsers.count
} else {
return users.count
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell?
if self.resultSearchController.active
{
let userFiltered = filteredUsers[indexPath.row]
cell!.textLabel?.text = userFiltered.name
} else {
let user = users[indexPath.row]
cell!.textLabel?.text = user.name
}
return cell!
}
//MARK: UITableviewDelegate
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let user = users[indexPath.row]
delegate.chreatChatroom(user)
tableView.deselectRowAtIndexPath(indexPath, animated: true)
self.dismissViewControllerAnimated(true, completion: nil)
}
//MARK: IBactions
@IBAction func cancelButtonPressed(sender: AnyObject) {
self.dismissViewControllerAnimated(true, completion: nil)
}
//MARK: Load Backendless Users
func loadUsers() {
let whereClause = "objectId != '\(backendless.userService.currentUser.objectId)'"
let dataQuery = BackendlessDataQuery()
dataQuery.whereClause = whereClause
let dataStore = backendless.persistenceService.of(BackendlessUser.ofClass())
dataStore.find(dataQuery, response: { (users : BackendlessCollection!) -> Void in
self.users = users.data as! [BackendlessUser]
self.resultSearchController = UISearchController(searchResultsController: nil)
self.resultSearchController.searchResultsUpdater = self
self.resultSearchController.dimsBackgroundDuringPresentation = false
self.resultSearchController.searchBar.sizeToFit()
self.tableView.tableHeaderView = self.resultSearchController.searchBar
self.tableView.reloadData()
}) { (fault : Fault!) -> Void in
print("Error, couldnt retrieve users: \(fault)")
}
}
}
答案 0 :(得分:2)
resultSearchController
nil
使用之前viewDidLoad()
。它设置在一个闭包中,在设置视图时,几乎可以确定在之后需要它。要解决此问题,只需将此初始化代码移至早期代码self.resultSearchController = UISearchController(searchResultsController: nil)
self.resultSearchController.searchResultsUpdater = self
self.resultSearchController.dimsBackgroundDuringPresentation = false
self.resultSearchController.searchBar.sizeToFit()
self.tableView.tableHeaderView = self.resultSearchController.searchBar
:
$Excel = New-Object -ComObject Excel.Application
$Workbook = $Excel.Workbooks.Open($FilePath)