swift - 使用不同的 View Controller 删除 map 上的数据

Question

我真的正在为一个我认为相当有趣且相当困难的问题而苦苦挣扎。我的应用程序允许用户在 map View 中创建注释位置。他们还可以选择在另一个模态视图 Controller 中编辑和删除这些位置。

我面临的问题是，当用户按下删除键(从 Firebase 中删除该位置)时，注释仍然显示在 map 上。我无法在确实出现的 View 中重新加载注释数据，因为这不适合我的应用程序。我不能每次打开 map View 时都重新加载注释。

我需要找到一种方法来实现按下删除按钮时重新加载注释。但是，由于这种情况发生在我的删除 View Controller (不包含 map View )中，我无法使用重新加载功能。有没有办法连接 View Controller ，以便我可以在按下删除时应用重新加载功能？

更新代码**

这是我的 map View Controller :

class ViewController: UIViewController, SideBarDelegate, MGLMapViewDelegate, DeleteVCDelegate {
let EditSaveSpotController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "EditVC") as! EditSaveSpotViewController

 override func viewDidLoad() {
    super.viewDidLoad()


    EditSaveSpotController.delegate = self

}


func wholeRefresh() {

    let uid = FIRAuth.auth()!.currentUser!.uid

    let userLocationsRef = FIRDatabase.database().reference(withPath: "users/\(uid)/personalLocations")

    userLocationsRef.observe(.value, with: { snapshot in


        for item in snapshot.children {
            guard let snapshot = item as? FIRDataSnapshot else { continue }

            let newSkatepark = Skatepark(snapshot: snapshot)

            self.skateparks.append(newSkatepark)

            self.addAnnotation(park: newSkatepark)


        }
    })

    if let annotations = mapView.annotations {

        mapView.removeAnnotations(annotations)

    }

    for item in skateparks {

        self.addAnnotation(park: item)

    }



}

这是我的删除 View Controller :

 import UIKit
 import Firebase

 protocol DeleteVCDelegate {
 func wholeRefresh()
 }

 class EditSaveSpotViewController: UIViewController  {
 var delegate: DeleteVCDelegate?


  @IBAction func deleteSkateSpot(_ sender: Any) {




    ref = FIRDatabase.database().reference(withPath: "users").child(Api.User.CURRENT_USER!.uid).child("personalLocations/\(parkId!)")

    ref.observe(.value, with: { (snapshot) in



        self.ref.setValue(nil)

        self.dismiss(animated: true, completion: nil)

        self.delegate?.wholeRefresh()

     //   self.delegate?.mainRefresh()

        print("CheckWorking")


    })



}

}

Answer 1

这是非常高的水平，我没有机会验证，但它应该足以让你继续:

模态删除 View

protocol DeleteVCDelegate {
    func mainRefresh()
}

class DeleteVC: UIViewController {
    var delegate: DeleteVCDelegate?

    //your delete code
    @IBAction func deleteSkateSpot(_ sender: Any) {
        ref = FIRDatabase.database().reference(withPath: "users").child(Api.User.CURRENT_USER!.uid).child("personalLocations/\(parkId!)")

        ref.observe(.value, with: { (snapshot) in
            self.ref.setValue(nil)

            //call to delegate
            self.delegate?.mainRefresh()
        })
    }
}

MapView类(实现DeleteVCDelegate)

class mapVC: MKMapViewDelegate, DeleteVCDelegate{

    //when you present your DeleteVC set its delegate to the map view
    let vc=(self.storyboard?.instantiateViewController(withIdentifier: "deleteVC"))! as! DeleteVC

    //set the delegate
    vc.delegate=self

    //present deleteVC
    self.present(vc, animated: true, completion:nil)

    //implement delegate method of DeleteVC
    func mainRefresh(){
        //dismiss modal
        self.dismiss(animated: true) { 
            //update view
            self.loadLocations()
            self.annotationRefresh()
        }

    }
}