带有范围过滤器的SearchBar导航栏内部

Question

我正在努力实现这一目标，但我的标题中有搜索栏

我正在添加搜索栏作为导航栏的子视图。当我将showScopeBar函数设置为true时，它会保持重叠并显示在搜索栏后面。我试过让导航栏的高度更大但没用。关于如何处理这个问题的任何建议？我不想将我的搜索栏添加到我的集合标题视图中。

import Foundation
import UIKit
import Firebase
 import FirebaseDatabase
 import FirebaseAuth

 class EventSearchController: UICollectionViewController, UISearchBarDelegate, UICollectionViewDelegateFlowLayout{

//resue identifier for the cell that you are constructing
let cellId = "cellID"

//ui search bar that will allow you to type in text and filter out results
//most of the code here is straight forward 
//must set delegate to self to get control over certain aspects of search bar
lazy var searchBar: UISearchBar = {
    let sb = UISearchBar()
    sb.placeholder = "Enter Event"
    sb.barTintColor = .gray
    UITextField.appearance(whenContainedInInstancesOf: [UISearchBar.self]).backgroundColor = UIColor.rgb(red: 230, green: 230, blue: 230)
    sb.delegate = self
    return sb
}()



//detects when search bar text is done editing
func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
    print("Stopped Editing")
    print(searchBar.text)
    guard let searchText = searchBar.text else{
        return
    }
    let lowerText = searchText.lowercased()
    fetchEvents(searchString: lowerText)


}

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String)
{
    if searchBar.text?.isEmpty == true
    {
        filteredEvents.removeAll()
        self.collectionView?.reloadData()
    }
}


func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
    //Changes the first responder to the search bar
    searchBar.resignFirstResponder()
}

// this function will detect change in the search bar and filter out the results returned based off what is entered in the search bar


override func viewDidLoad() {
    super.viewDidLoad()
    collectionView?.backgroundColor = .white

    navigationController?.navigationBar.addSubview(searchBar)

    let navBar = navigationController?.navigationBar

    searchBar.anchor(top: navBar?.topAnchor, left: navBar?.leftAnchor, bottom: navBar?.bottomAnchor, right: navBar?.rightAnchor, paddingTop: 0, paddingLeft: 8, paddingBottom: 0, paddingRight: 8, width: 0, height: 0)
    //will register a cell to the screen
    //notice the EventSearchCell that is one of the parameters
    //that is there so it creates the cell in the way that I want it to based off the EventSearchCell Swift File
 self.collectionView?.register(EventSearchCell.self, forCellWithReuseIdentifier: cellId)
    collectionView?.alwaysBounceVertical = true
    collectionView?.keyboardDismissMode = .onDrag

}
//two arrays both of type Event
//one for appending the results of the database search
//one for grabbing the results of the search bar
var filteredEvents = [Event]()
var eventsArray = [Event]()
fileprivate func fetchEvents(searchString: String){
    print("Fetching events....")
    //create a reference to the location in the database that you want to pull from and observe the value there
    let ref = Database.database().reference().child("events")
    // this will retur a snapshot with all the data at that location in the database and cast the results as a dictionary for later use
    let endString = searchString + "\\uf8ff"
    let query = ref.queryOrdered(byChild: "event:name").queryStarting(atValue: searchString).queryEnding(atValue: endString)
    print(query)
    query.observeSingleEvent(of: .value, with: { (snapshot) in
        guard let dictionary = snapshot.value as? [String: Any] else{
            print(snapshot.value)
            return
        }
        print(snapshot.value)
        dictionary.forEach({ (key,value) in
            print(key,value)
            guard let eventDictionary = value as? [String: Any] else{
                return
            }
            let events = Event(currentEventKey: key, dictionary:eventDictionary)

            let filteredEvents = self.eventsArray.filter { (event) -> Bool in
                return event.currentEventKey == events.currentEventKey
            }

            if filteredEvents.count == 0 {
                //append
                self.eventsArray.append(events)
            }


            self.filteredEvents = self.eventsArray.filter { (event) -> Bool in
                return event.currentEventName.lowercased().contains(searchString.lowercased())

            }
            DispatchQueue.main.async {
                self.collectionView?.reloadData()
            }


        })


    }) { (err) in
        print("Failed to fetch event data", err)
    }



}

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    //make sure that the screen is loaded with the proper number of cells when you first go to the screen
    return filteredEvents.count
}

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    searchBar.isHidden = true
    searchBar.resignFirstResponder()
  let event = filteredEvents[indexPath.item]
    print(event.currentEventKey)
    let currentEventDetailController = EventDetailViewController()
    currentEventDetailController.eventImage = event.currentEventImage
    currentEventDetailController.eventName = event.currentEventName
    currentEventDetailController.eventDescription = event.currentEventDescription
    currentEventDetailController.eventStreet = event.currentEventStreetAddress
    currentEventDetailController.eventCity = event.currentEventCity
    currentEventDetailController.eventState = event.currentEventState
    currentEventDetailController.eventZip = event.currentEventZip
    currentEventDetailController.eventKey = event.currentEventKey

    self.filteredEvents.removeAll(keepingCapacity: true)
    self.eventsArray.removeAll(keepingCapacity: true)
    self.collectionView?.reloadData()
    navigationController?.pushViewController(currentEventDetailController, animated: true)
}


override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    searchBar.text = ""
    self.collectionView?.reloadData()
    filteredEvents.removeAll()
    searchBar.isHidden = false
}

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    //creates a cell and cast it as the Appropriate type
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! EventSearchCell
    cell.event = filteredEvents[indexPath.row]
    return cell
}

//constrols size of the cell
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    return CGSize(width: view.frame.width, height: 66)
}

}