版本記錄

前言

3D Touch是一種立體觸控技術(shù)兜挨，被蘋果稱為新一代多點(diǎn)觸控技術(shù)，是在Apple Watch上采用的Force Touch眯分，屏幕可感應(yīng)不同的感壓力度觸控拌汇。3D Touch，蘋果iPhone 6s以后的機(jī)型中出現(xiàn)的新功能弊决，看起來(lái)類似 PC 上的右鍵噪舀。有Peek Pop 兩種新手勢(shì)。2015年9月10日飘诗，蘋果在新品發(fā)布會(huì)上宣布了3D Touch功能与倡。Force Touch和3Dtouch其實(shí)是基于同一種技術(shù)，且都基于蘋果的Taptic引擎昆稿，但是不管你承不承認(rèn)或者有沒有意識(shí)到纺座，3D Touch的確更優(yōu)于Force Touch。接下來(lái)這個(gè)專題我們就看一下3D Touch相關(guān)的內(nèi)容溉潭。

開始

首先看一下寫作環(huán)境净响。

Swift 4.2, iOS 12, Xcode 10

自Apple推出3D Touch以及iPhone 6S以來(lái)，用戶已經(jīng)能夠使用新的喳瓣，備用的馋贤，基于觸摸的交互來(lái)訪問應(yīng)用程序中的功能。 通過給屏幕提供不同程度的壓力畏陕，用戶可以使用Peek預(yù)覽頁(yè)面配乓，然后Pop到預(yù)覽頁(yè)面。 通過使用3D Touch增強(qiáng)您的應(yīng)用程序，您可以為用戶提供更加身臨其境的專業(yè)體驗(yàn)扰付。

以下是您將在本文中執(zhí)行的操作：

• 在Storyboard中實(shí)現(xiàn)Peek和Pop堤撵。
• 以編程方式處理Peek和Pop。
• Peeking時(shí)自定義內(nèi)容大小羽莺。
• 在Peeking時(shí)提供action实昨。

注意：雖然iOS模擬器確實(shí)支持3D Touch，但您的計(jì)算機(jī)或觸控板必須啟用強(qiáng)制觸控盐固。 即使啟用了強(qiáng)制觸控功能荒给，手勢(shì)仍然很棘手。 如果可能的話刁卜，我建議您使用支持3D Touch的設(shè)備志电。

打開已經(jīng)準(zhǔn)備好的備用工程，看一下sb中的內(nèi)容蛔趴。

Build并運(yùn)行如下顯示：

Adding Peek and Pop - 添加Peek和Pop

打開Main.storyboard并找到All Geotifications場(chǎng)景的segue挑辆，ShowGeotification，并通過選中Preview＆Commit Segues的復(fù)選框啟用Peek＆Pop孝情。

構(gòu)建并運(yùn)行應(yīng)用程序鱼蝉。 確保您在應(yīng)用中至少有一個(gè)地理位置的位置。 選擇“書簽”圖標(biāo)箫荡，導(dǎo)航到All Geotifications魁亦。 使用3D Touch接合表格中的第一行。 如果您不熟悉使用3D Touch羔挡，請(qǐng)?jiān)诓煌潭鹊膲毫ο逻M(jìn)行操作洁奈，看看Peek與Pop需要多少壓力。

如果您正在尋找3D Touch的快速實(shí)現(xiàn)绞灼，利用Storyboard的內(nèi)置功能是一個(gè)輕松的勝利利术。

Custom Handling - 自定義處理

使用Storyboard將3D Touch集成到您的應(yīng)用程序非常簡(jiǎn)單，您可能會(huì)遇到一些情況镀赌，您需要更好地控制在peek or pop期間發(fā)生的事情 - 或者您甚至不使用Interface Builder的情況氯哮。 但是，這不需要您付出太多努力商佛。

首先，您要將3D Touch添加到地圖上所有Geotification pins的MKPinAnnotationView中姆打。

打開GeotificationsViewController.swift良姆，并在mapView（_：viewFor :)中，在以下行下面：

annotationView?.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)

添加下面代碼

if let annotationView = annotationView,
  // 1.
  traitCollection.forceTouchCapability == .available {
  // 2. 
  registerForPreviewing(with: self, sourceView: annotationView)
}

在以編程方式實(shí)現(xiàn)3D Touch之前幔戏，您需要做兩件事：

• 1） 檢查設(shè)備上是否有3D Touch非常重要玛追。 視圖控制器的trait collection使用forceTouchCapability屬性提供了一種簡(jiǎn)單的方法。
• 2） 如果您的設(shè)備支持3D Touch，您只需調(diào)用registerForPreviewing（with：sourceView :)痊剖。 在這里韩玩，您將視圖控制器作為委托，并將annotation view作為源視圖陆馁。 這意味著找颓，當(dāng)您使用3D Touch來(lái)啟用annotation view時(shí)，它將成為Peek或預(yù)覽控制器的源叮贩。

接下來(lái)击狮，將以下擴(kuò)展名添加到文件末尾：

// MARK: - UIViewController Previewing Delegate

extension GeotificationsViewController: UIViewControllerPreviewingDelegate {
  func previewingContext(_ previewingContext: UIViewControllerPreviewing,
                         viewControllerForLocation location: CGPoint) 
    -> UIViewController? {
     // 1.
    guard let annotationView = previewingContext.sourceView as? MKPinAnnotationView,
      let annotation = annotationView.annotation as? Geotification,
      let addGeotificationViewController = storyboard?
        .instantiateViewController(withIdentifier: "AddGeotificationViewController")
        as? AddGeotificationViewController else { return nil }
    addGeotificationViewController.geotification = annotation
    addGeotificationViewController.delegate = self
    
    // 2.
    addGeotificationViewController.preferredContentSize =
      CGSize(width: 0, height: 360)
    return addGeotificationViewController  }
  
  func previewingContext(_ previewingContext: UIViewControllerPreviewing,
                         commit viewControllerToCommit: UIViewController) {
    // 3.
    navigationController?.show(viewControllerToCommit, sender: nil)
  }
}

為了完成3D Touch的工作，您需要采用UIViewControllerPreviewingDelegate益老。因?yàn)槟炎?cè)annotation view以與3D觸摸交互彪蓬，previewContext（_：viewControllerForLocation :)里就是你將在Peeks和Pops期間展示的視圖控制器。

• 1） previewingContext使您可以訪問觸摸源捺萌。如果您注冊(cè)了多個(gè)源視圖档冬，則可以區(qū)分這些視圖。一旦知道源視圖是map annotation桃纯，就可以創(chuàng)建AddGeotificationViewController酷誓。
• 2） 默認(rèn)情況下，預(yù)覽的大小將填充設(shè)備的大部分屏幕慈参。在這種情況下呛牲，有太多的空白，減少預(yù)覽的大小看起來(lái)會(huì)更好驮配。在這里娘扩，您只需更改addGeotificationViewController的preferred Content Size的高度。 iOS會(huì)自動(dòng)為您處理寬度壮锻。
• 3） 最后琐旁，您需要提供有關(guān)Peek將Pop的信息。在previewingContext（_：commit）中猜绣，您可以處理用戶應(yīng)該如何導(dǎo)航到previewed的視圖控制器灰殴，這里只需pushing到導(dǎo)航堆棧即可。

Build并運(yùn)行掰邢。點(diǎn)擊annotation’s pin牺陶，然后在注釋視圖上啟動(dòng)3D Touch。您現(xiàn)在將看到您的預(yù)覽更適合其內(nèi)容視圖辣之。

使用Storyboard處理Peeking時(shí)掰伸，您也可以完成相同的效果。 打開ListTableViewController.swift并用以下內(nèi)容替換prepare（for：sender）：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
  if segue.identifier == "ShowGeotification" {
    guard let addViewController =
      segue.destination as? AddGeotificationViewController,
      let cell = sender as? UITableViewCell,
      let indexPath = tableView.indexPath(for: cell) else { return }
    addViewController.geotification =
      GeotificationManager.shared.geotifications[indexPath.row]
    addViewController.delegate = self
    addViewController.preferredContentSize = CGSize(width: 0, height: 360)
  }
}

Build并運(yùn)行怀估。 然后狮鸭，導(dǎo)航回Geotifications列表合搅。 現(xiàn)在，當(dāng)您使用3D Touch接合單元格時(shí)歧蕉，您將看到預(yù)覽的視圖控制器的大小已更改灾部。 無(wú)論您是編寫UI代碼還是使用Storyboard的純粹主義者，您都會(huì)發(fā)現(xiàn)它并不需要做太多工作惯退。

Adding Actions - 添加動(dòng)作

雖然使用3D Touch預(yù)覽和導(dǎo)航到視圖很酷赌髓，但您可以做更多的事情來(lái)為此功能增加價(jià)值。 您可能在電子郵件中的3D觸摸式回復(fù)或轉(zhuǎn)發(fā)過程中遇到過操作蒸痹，或者查看Apple Music中的某首歌曲可用的所有選項(xiàng)時(shí)春弥。 為自己添加這些稱為UIPreviewActions的選項(xiàng)仍然與添加3D Touch的前面步驟一樣簡(jiǎn)單。

打開AddGeotificationViewController.swift并將以下協(xié)議方法添加到AddGeotificationsViewControllerDelegate：

func addGeotificationViewController(_ controller: AddGeotificationViewController,
                                      didSelect action: UIPreviewAction,
                                      for previewedController: UIViewController)

如果調(diào)用preview action叠荠，將在AddGeotificationViewController的委托上調(diào)用此方法匿沛。

現(xiàn)在，在屬性列表之后榛鼎，將以下屬性和方法添加到AddGeotificationViewController：

override var previewActionItems: [UIPreviewActionItem] {
  let editAction = UIPreviewAction(title: "Edit", style: .default) {
    [weak self] (action, controller) in
    self?.handle(action: action, and: controller)
  }
  let deleteAction = UIPreviewAction(title: "Delete", style: .destructive) {
    [weak self] (action, controller) in
    self?.handle(action: action, and: controller)
  }
  return [editAction, deleteAction]
}

private func handle(action: UIPreviewAction, and controller: UIViewController) {
  delegate?.addGeotificationViewController(self, didSelect: action, for: controller)
}

為了讓用戶在Peek期間查看操作逃呼，正在預(yù)覽的視圖控制器必須重寫previewActionItems并返回UIPreviewActionItems數(shù)組。 在這里者娱，您添加了Edit 和 Delete操作抡笼。 他們的兩個(gè)處理程序都調(diào)用handle（action：and:)，它調(diào)用你之前添加的委托方法黄鳍。 要處理這些操作推姻，您需要在兩個(gè)位置實(shí)現(xiàn)此方法。

首先框沟，打開GeotificationsViewController.swift并將以下代碼添加到AddGeotificationsViewControllerDelegate擴(kuò)展：

func addGeotificationViewController(_ controller: AddGeotificationViewController,
                                    didSelect action: UIPreviewAction,
                                    for previewedController: UIViewController) {
  switch action.title {
  case "Edit":
    navigationController?.show(previewedController, sender: nil)
  case "Delete":
    guard let addGeotificationViewController = previewedController
      as? AddGeotificationViewController,
      let geotification = addGeotificationViewController.geotification else { return }
    remove(geotification)
  default:
    break
  }
}

接下來(lái)藏古，打開ListTableViewController.swift，并將以下代碼添加到AddGeotificationsViewControllerDelegate擴(kuò)展：

func addGeotificationViewController(_ controller: AddGeotificationViewController,
                                    didSelect action: UIPreviewAction,
                                    for previewedController: UIViewController) {
  switch action.title {
  case "Edit":
    navigationController?.show(previewedController, sender: nil)
  case "Delete":
    guard let addGeotificationViewController = previewedController
      as? AddGeotificationViewController,
      let geotification = addGeotificationViewController.geotification else { return }
    GeotificationManager.shared.remove(geotification)
    tableView.reloadData()
  default:
    break
  }
}

這兩種方法都提供了處理您添加到Peek中的兩個(gè)操作的方法忍燥。 如果調(diào)用Edit操作拧晕，則推送視圖控制器。 調(diào)用Delete時(shí)梅垄，將從地圖和存儲(chǔ)中刪除Geotification厂捞。

Build并運(yùn)行。 要查看預(yù)覽操作队丝，請(qǐng)?jiān)诳吹筋A(yù)覽時(shí)啟動(dòng)3D Touch并向上滑動(dòng)靡馁。 您應(yīng)該注意到預(yù)覽頂部有一個(gè)白色箭頭，表示存在操作机久。 一旦看到動(dòng)作奈嘿，您就可以自由地將手指從屏幕上抬起。

Grouping Preview Actions - 分組預(yù)覽操作

如果您希望以不同方式對(duì)預(yù)覽操作進(jìn)行分組吞加，則可以使用UIPreviewActionGroup。 這使您可以通過隱藏單個(gè)操作后面的更多操作來(lái)提供有關(guān)您的操作如何相互關(guān)聯(lián)的更多上下文。

要嘗試此操作衔憨，請(qǐng)打開AddGeotificationViewController.swift叶圃，并將previewActionItems替換為以下內(nèi)容：

override var previewActionItems: [UIPreviewActionItem] {
  let editAction = UIPreviewAction(title: "Edit", style: .default) {
    [weak self] (action, controller) in
    self?.handle(action: action, and: controller)
  }
  
  let deleteAction = UIPreviewAction(title: "Delete", style: .destructive) {
    [weak self] (action, controller) in
    self?.handle(action: action, and: controller)
  }
  let cancelAction = UIPreviewAction(title: "Cancel", style: .default) {
    [weak self] (action, controller) in
    self?.handle(action: action, and: controller)
  }
  let group = UIPreviewActionGroup(title: "Delete...",
                                   style: .destructive,
                                   actions: [cancelAction, deleteAction])
  return [editAction, group]
}

通過將deleteAction和cancelAction添加到group的操作，您將在選擇Delete時(shí)獲得一組額外的選項(xiàng)践图。

Build并運(yùn)行應(yīng)用程序掺冠。 當(dāng)您選擇Delete時(shí)，您現(xiàn)在將看到第二個(gè)預(yù)覽操作码党，即原始Delete德崭。 如果您不想刪除地理定位，這將使您有機(jī)會(huì)改變主意揖盘。

有了這個(gè)眉厨，您已經(jīng)完成了3D Touch在應(yīng)用程序的添加。 看看您是否可以找到要添加到Peek的新操作兽狭，或者為自己實(shí)現(xiàn)3D Touch的地方憾股。

源碼

1. Swift源碼

1. AppDelegate.swift

import UIKit
import CoreLocation
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
  var window: UIWindow?
  let locationManager = CLLocationManager()
  
  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions:[UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
    locationManager.delegate = self
    locationManager.requestAlwaysAuthorization()
    let options: UNAuthorizationOptions = [.badge, .sound, .alert]
    UNUserNotificationCenter.current()
      .requestAuthorization(options: options) { success, error in
        if let error = error {
          print("Error: \(error)")
        }
    }
    
    return true
  }
  
  func applicationDidBecomeActive(_ application: UIApplication) {
    application.applicationIconBadgeNumber = 0
    UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
    UNUserNotificationCenter.current().removeAllDeliveredNotifications()
  }
  
  func handleEvent(for region: CLRegion!) {
    // Show an alert if application is active
    if UIApplication.shared.applicationState == .active {
      guard let message = note(from: region.identifier) else { return }
      window?.rootViewController?.showAlert(withTitle: nil, message: message)
    } else {
      // Otherwise present a local notification
      guard let body = note(from: region.identifier) else { return }
      let notificationContent = UNMutableNotificationContent()
      notificationContent.body = body
      notificationContent.sound = UNNotificationSound.default
      notificationContent.badge = UIApplication.shared.applicationIconBadgeNumber + 1 as NSNumber
      let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
      let request = UNNotificationRequest(identifier: "location_change",
                                          content: notificationContent,
                                          trigger: trigger)
      UNUserNotificationCenter.current().add(request) { error in
        if let error = error {
          print("Error: \(error)")
        }
      }
    }
  }
  
  func note(from identifier: String) -> String? {
    guard let matched = GeotificationManager.shared.geotifications.filter({
      $0.identifier == identifier
    }).first else { return nil }
    return matched.note
  }
}

extension AppDelegate: CLLocationManagerDelegate {
  func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
    if region is CLCircularRegion {
      handleEvent(for: region)
    }
  }
  
  func locationManager(_ manager: CLLocationManager, didExitRegion region: CLRegion) {
    if region is CLCircularRegion {
      handleEvent(for: region)
    }
  }
}

2. GeotificationsViewController.swift

import UIKit
import MapKit
import CoreLocation

class GeotificationsViewController: UIViewController {
  @IBOutlet weak var mapView: MKMapView!
  private var locationManager = CLLocationManager()
  
  override func viewDidLoad() {
    super.viewDidLoad()
    locationManager.delegate = self
    locationManager.requestAlwaysAuthorization()
    GeotificationManager.shared.geotifications.forEach {
      addToMap($0)
    }
  }
  
  // MARK: - Segues
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "addGeotification" {
      guard let addViewController = segue.destination as? AddGeotificationViewController else { return }
      addViewController.delegate = self
    }
  }
  
  @IBAction func listExit(segue: UIStoryboardSegue) {
    mapView.removeAnnotations(mapView.annotations)
    GeotificationManager.shared.geotifications.forEach {
      addToMap($0)
    }
    if GeotificationManager.shared.geotifications.isEmpty {
      updateGeotificationsCount()
    }
  }
  
  // MARK: Functions that update the model/associated views with geotification changes
  func add(_ geotification: Geotification) {
    GeotificationManager.shared.geotifications.append(geotification)
    addToMap(geotification)
  }
  
  private func addToMap(_ geotification: Geotification) {
    mapView.addAnnotation(geotification)
    addRadiusOverlay(forGeotification: geotification)
    updateGeotificationsCount()
  }
  
  func remove(_ geotification: Geotification) {
    GeotificationManager.shared.remove(geotification)
    mapView.removeAnnotation(geotification)
    removeRadiusOverlay(forGeotification: geotification)
    updateGeotificationsCount()
  }
  
  private func updateGeotificationsCount() {
    let count = GeotificationManager.shared.geotifications.count
    title = "Geotifications: \(count)"
    navigationItem.rightBarButtonItem?.isEnabled = (count < 20)
  }
  
  // MARK: Map overlay functions
  private func addRadiusOverlay(forGeotification geotification: Geotification) {
    mapView?.addOverlay(MKCircle(center: geotification.coordinate, radius: geotification.radius))
  }
  
  private func removeRadiusOverlay(forGeotification geotification: Geotification) {
    // Find exactly one overlay which has the same coordinates & radius to remove
    guard let overlays = mapView?.overlays else { return }
    for overlay in overlays {
      guard let circleOverlay = overlay as? MKCircle else { continue }
      let coord = circleOverlay.coordinate
      if coord.latitude == geotification.coordinate.latitude && coord.longitude == geotification.coordinate.longitude && circleOverlay.radius == geotification.radius {
        mapView?.removeOverlay(circleOverlay)
        break
      }
    }
  }
  
  // MARK: Other mapview functions
  @IBAction func zoomToCurrentLocation(sender: AnyObject) {
    mapView.zoomToUserLocation()
  }
}

// MARK: - Location Manager Delegate
extension GeotificationsViewController: CLLocationManagerDelegate {
  func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
    mapView.showsUserLocation = status == .authorizedAlways
  }
  
  func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
    print("Location Manager failed with the following error: \(error)")
  }
}

// MARK: - MapView Delegate
extension GeotificationsViewController: MKMapViewDelegate {
  func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    let identifier = "myGeotification"
    if annotation is Geotification {
      var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as? MKPinAnnotationView
      if annotationView == nil {
        annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
        annotationView?.canShowCallout = true
        let removeButton = UIButton(type: .custom)
        removeButton.frame = CGRect(x: 0, y: 0, width: 23, height: 23)
        removeButton.setImage(UIImage(named: "DeleteGeotification")!, for: .normal)
        annotationView?.leftCalloutAccessoryView = removeButton
        annotationView?.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)
        if let annotationView = annotationView,
          // 1.
          traitCollection.forceTouchCapability == .available {
          // 2.
          registerForPreviewing(with: self, sourceView: annotationView)
        }
      } else {
        annotationView?.annotation = annotation
      }
      return annotationView
    }
    return nil
  }
  
  func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
    if overlay is MKCircle {
      let circleRenderer = MKCircleRenderer(overlay: overlay)
      circleRenderer.lineWidth = 1.0
      circleRenderer.strokeColor = .purple
      circleRenderer.fillColor = UIColor.purple.withAlphaComponent(0.4)
      return circleRenderer
    }
    return MKOverlayRenderer(overlay: overlay)
  }
  
  func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {
    if control == view.rightCalloutAccessoryView {
      guard let annotation = view.annotation as? Geotification,
        let addGeotificationViewController = storyboard?.instantiateViewController(withIdentifier: "AddGeotificationViewController") as? AddGeotificationViewController else { return }
      addGeotificationViewController.geotification = annotation
      addGeotificationViewController.delegate = self
      navigationController?.show(addGeotificationViewController, sender: nil)
    } else {
      let geotification = view.annotation as! Geotification
      remove(geotification)
    }
  }
}

// MARK: AddGeotificationViewControllerDelegate
extension GeotificationsViewController: AddGeotificationsViewControllerDelegate {
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didAdd geotification: Geotification) {
    navigationController?.popViewController(animated: true)
    GeotificationManager.shared.add(geotification)
    addToMap(geotification)
  }
  
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didChange oldGeotifcation: Geotification, to newGeotification: Geotification) {
    navigationController?.popViewController(animated: true)
    remove(oldGeotifcation)
    GeotificationManager.shared.add(newGeotification)
    addToMap(newGeotification)
  }
  
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didSelect action: UIPreviewAction, for previewedController: UIViewController) {
    switch action.title {
    case "Edit":
      navigationController?.show(previewedController, sender: nil)
    case "Delete":
      guard let addGeotificationViewController = previewedController as? AddGeotificationViewController,
        let geotification = addGeotificationViewController.geotification else { return }
      remove(geotification)
    default:
      break
    }
  }
}

// MARK: - UIViewController Previewing Delegate
extension GeotificationsViewController: UIViewControllerPreviewingDelegate {
  func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
      // 1.
      guard let annotationView = previewingContext.sourceView as? MKPinAnnotationView,
        let annotation = annotationView.annotation as? Geotification,
        let addGeotificationViewController = storyboard?.instantiateViewController(withIdentifier: "AddGeotificationViewController") as? AddGeotificationViewController else { return nil }
      addGeotificationViewController.geotification = annotation
      addGeotificationViewController.delegate = self
      
      // 2.
      addGeotificationViewController.preferredContentSize = CGSize(width: 0, height: 360)
      return addGeotificationViewController
  }
  
  func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
    // 3.
    navigationController?.show(viewControllerToCommit, sender: nil)
  }
}

3. ListTableViewController.swift

import UIKit

class ListTableViewController: UITableViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
  }
  
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "ShowGeotification" {
      guard let addViewController = segue.destination as? AddGeotificationViewController,
        let cell = sender as? UITableViewCell,
        let indexPath = tableView.indexPath(for: cell) else { return }
      addViewController.geotification = GeotificationManager.shared.geotifications[indexPath.row]
      addViewController.delegate = self
    }
  }
  
}

// MARK: - Table view data source
extension ListTableViewController {
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return GeotificationManager.shared.geotifications.count
  }
  
  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "GeotificationCell", for: indexPath)
    let geotification = GeotificationManager.shared.geotifications[indexPath.row]
    cell.textLabel?.text = geotification.title
    cell.detailTextLabel?.text = geotification.subtitle
    return cell
  }
}

// MARK: - Table View Delegate
extension ListTableViewController {
  override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
    return true
  }
  
  // Override to support editing the table view.
  override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
    guard indexPath.row < GeotificationManager.shared.geotifications.count else { return }
    if editingStyle == .delete {
      tableView.beginUpdates()
      GeotificationManager.shared.remove(GeotificationManager.shared.geotifications[indexPath.row])
      tableView.deleteRows(at: [indexPath], with: .fade)
      tableView.endUpdates()
    }
  }
}

// MARK: - AddGeotificationsViewControllerDelegate

extension ListTableViewController: AddGeotificationsViewControllerDelegate {
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didAdd geotification: Geotification) {}
  
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didChange oldGeotifcation: Geotification, to newGeotification: Geotification) {
    navigationController?.popViewController(animated: true)
    GeotificationManager.shared.remove(oldGeotifcation)
    GeotificationManager.shared.add(newGeotification)
  }
  
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didSelect action: UIPreviewAction, for previewedController: UIViewController) {
    switch action.title {
    case "Edit":
      navigationController?.show(previewedController, sender: nil)
    case "Delete":
      guard let addGeotificationViewController = previewedController as? AddGeotificationViewController,
        let geotification = addGeotificationViewController.geotification else { return }
      GeotificationManager.shared.remove(geotification)
      tableView.reloadData()
    default:
      break
    }
  }
}

4. AddGeotificationViewController.swift

import UIKit
import MapKit
import CoreLocation

protocol AddGeotificationsViewControllerDelegate {
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didAdd geotification: Geotification)
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didChange oldGeotifcation: Geotification, to newGeotification: Geotification)
  func addGeotificationViewController(_ controller: AddGeotificationViewController, didSelect action: UIPreviewAction, for previewedController: UIViewController)
}

class AddGeotificationViewController: UITableViewController {
  @IBOutlet var addButton: UIBarButtonItem!
  @IBOutlet var zoomButton: UIBarButtonItem!
  @IBOutlet weak var eventTypeSegmentedControl: UISegmentedControl!
  @IBOutlet weak var radiusTextField: UITextField!
  @IBOutlet weak var noteTextField: UITextField!
  @IBOutlet weak var mapView: MKMapView!
  
  var delegate: AddGeotificationsViewControllerDelegate?
  var geotification: Geotification?
  
  override var previewActionItems: [UIPreviewActionItem] {
    let editAction = UIPreviewAction(title: "Edit", style: .default) { [weak self] (action, controller) in
      self?.handle(action: action, and: controller)
    }
    
    let deleteAction = UIPreviewAction(title: "Delete", style: .destructive) { [weak self] (action, controller) in
      self?.handle(action: action, and: controller)
    }
    let cancelAction = UIPreviewAction(title: "Cancel", style: .default) { [weak self] (action, controller) in
      self?.handle(action: action, and: controller)
    }
    let group = UIPreviewActionGroup(title: "Delete...", style: .destructive, actions: [cancelAction, deleteAction])
    return [editAction, group]
  }
  
  private func handle(action: UIPreviewAction, and controller: UIViewController) {
    delegate?.addGeotificationViewController(self, didSelect: action, for: controller)
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    navigationItem.rightBarButtonItems = [addButton, zoomButton]
    addButton.isEnabled = false
    if let geotification = geotification {
      setup(geotification)
    }
  }
  
  private func setup(_ geotification: Geotification) {
    title = "Edit Geotification"
    eventTypeSegmentedControl.selectedSegmentIndex = geotification.eventType == .onEntry ? 0 : 1
    radiusTextField.text = String(Int(geotification.radius))
    noteTextField.text = geotification.note
    mapView.setCenter(geotification.coordinate, animated: false)
    addButton.title = "Save"
    addButton.isEnabled = true
  }
  
  @IBAction func textFieldEditingChanged(sender: UITextField) {
    addButton.isEnabled = !radiusTextField.text!.isEmpty && !noteTextField.text!.isEmpty
  }
  
  @IBAction func onCancel(sender: AnyObject) {
    navigationController?.popViewController(animated: true)
  }
  
  @IBAction private func onAdd(sender: AnyObject) {
    let coordinate = mapView.centerCoordinate
    let radius = Double(radiusTextField.text!) ?? 0
    let identifier = NSUUID().uuidString
    let note = noteTextField.text ?? ""
    let eventType: Geotification.EventType = (eventTypeSegmentedControl.selectedSegmentIndex == 0) ? .onEntry : .onExit
    if let geotification = geotification {
      let oldGeotification = geotification
      geotification.coordinate = coordinate
      geotification.radius = radius
      geotification.note = note
      geotification.eventType = eventType
      delegate?.addGeotificationViewController(self, didChange: oldGeotification, to: geotification)
    } else {
      let clampedRadius = min(radius, CLLocationManager().maximumRegionMonitoringDistance)
      let geotification = Geotification(coordinate: coordinate, radius: clampedRadius, identifier: identifier, note: note, eventType: eventType)
      delegate?.addGeotificationViewController(self, didAdd: geotification)
    }
  }
  
  @IBAction private func onZoomToCurrentLocation(sender: AnyObject) {
    mapView.zoomToUserLocation()
  }
}

5. Geotification.swift

import UIKit
import MapKit
import CoreLocation

class Geotification: NSObject, Codable, MKAnnotation {
  enum EventType: String {
    case onEntry = "On Entry"
    case onExit = "On Exit"
  }
  
  enum CodingKeys: String, CodingKey {
    case latitude, longitude, radius, identifier, note, eventType
  }
  
  var coordinate: CLLocationCoordinate2D
  var radius: CLLocationDistance
  var identifier: String
  var note: String
  var eventType: EventType
  
  var title: String? {
    if note.isEmpty {
      return "No Note"
    }
    return note
  }
  
  var subtitle: String? {
    let eventTypeString = eventType.rawValue
    return "Radius: \(radius)m - \(eventTypeString)"
  }
  
  init(coordinate: CLLocationCoordinate2D, radius: CLLocationDistance, identifier: String, note: String, eventType: EventType) {
    self.coordinate = coordinate
    self.radius = radius
    self.identifier = identifier
    self.note = note
    self.eventType = eventType
  }
  
  // MARK: Codable
  required init(from decoder: Decoder) throws {
    let values = try decoder.container(keyedBy: CodingKeys.self)
    let latitude = try values.decode(Double.self, forKey: .latitude)
    let longitude = try values.decode(Double.self, forKey: .longitude)
    coordinate = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    radius = try values.decode(Double.self, forKey: .radius)
    identifier = try values.decode(String.self, forKey: .identifier)
    note = try values.decode(String.self, forKey: .note)
    let event = try values.decode(String.self, forKey: .eventType)
    eventType = EventType(rawValue: event) ?? .onEntry
  }
  
  func encode(to encoder: Encoder) throws {
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(coordinate.latitude, forKey: .latitude)
    try container.encode(coordinate.longitude, forKey: .longitude)
    try container.encode(radius, forKey: .radius)
    try container.encode(identifier, forKey: .identifier)
    try container.encode(note, forKey: .note)
    try container.encode(eventType.rawValue, forKey: .eventType)
  }
  
}

6. GeotificationManager.swift

import Foundation
import CoreLocation

struct PreferencesKeys {
  static let savedItems = "savedItems"
}

class GeotificationManager: NSObject {
  static let shared = GeotificationManager.init()
  
  var geotifications: [Geotification] = []
  private let locationManager = CLLocationManager()
  
  private override init() {
    super.init()
    locationManager.delegate = self
    guard let savedData = UserDefaults.standard.data(forKey: PreferencesKeys.savedItems) else {
      return
    }
    let decoder = JSONDecoder()
    if let savedGeotifications = try? decoder.decode(Array.self, from: savedData) as [Geotification] {
      geotifications = savedGeotifications
    }
  }
  
  public func add(_ geotification: Geotification) {
    geotifications.append(geotification)
    startMonitoring(geotification: geotification)
    saveAllGeotifications()
  }
  
  public func remove(_ geotification: Geotification) {
    guard let index = GeotificationManager.shared.geotifications.index(of: geotification) else { return }
    geotifications.remove(at: index)
    stopMonitoring(geotification: geotification)
    saveAllGeotifications()
  }
  
  private func saveAllGeotifications() {
    let encoder = JSONEncoder()
    do {
      let data = try encoder.encode(geotifications)
      UserDefaults.standard.set(data, forKey: PreferencesKeys.savedItems)
    } catch {
      print("error encoding geotifications")
    }
  }
  
  private func region(with geotification: Geotification) -> CLCircularRegion {
    let region = CLCircularRegion(center: geotification.coordinate, radius: geotification.radius, identifier: geotification.identifier)
    region.notifyOnEntry = (geotification.eventType == .onEntry)
    region.notifyOnExit = !region.notifyOnEntry
    return region
  }
  
  private func startMonitoring(geotification: Geotification) {
    if !CLLocationManager.isMonitoringAvailable(for: CLCircularRegion.self) {
      print("Geofencing is not supported on this device!")
      return
    }
    
    if CLLocationManager.authorizationStatus() != .authorizedAlways {
      let message = """
      Your geotification is saved but will only be activated once you grant
      Geotify permission to access the device location.
      """
      print(message)
    }
    
    let fenceRegion = region(with: geotification)
    locationManager.startMonitoring(for: fenceRegion)
  }
  
  private func stopMonitoring(geotification: Geotification) {
    for region in locationManager.monitoredRegions {
      guard let circularRegion = region as? CLCircularRegion, circularRegion.identifier == geotification.identifier else { continue }
      locationManager.stopMonitoring(for: circularRegion)
    }
  }
}

extension GeotificationManager: CLLocationManagerDelegate {
  func locationManager(_ manager: CLLocationManager, monitoringDidFailFor region: CLRegion?, withError error: Error) {
    print("Monitoring failed for region with identifier: \(region!.identifier)")
  }
}

7. Utilities.swift

import UIKit
import MapKit

// MARK: Helper Extensions
extension UIViewController {
  func showAlert(withTitle title: String?, message: String?) {
    let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
    let action = UIAlertAction(title: "OK", style: .cancel, handler: nil)
    alert.addAction(action)
    present(alert, animated: true, completion: nil)
  }
}

extension MKMapView {
  func zoomToUserLocation() {
    guard let coordinate = userLocation.location?.coordinate else { return }
    let region = MKCoordinateRegion(center: coordinate, latitudinalMeters: 10000, longitudinalMeters: 10000)
    setRegion(region, animated: true)
  }
}

后記

本篇主要講述了基于3D Touch的Peek 和 Pop，感興趣的給個(gè)贊或者關(guān)注~~~