Question

我想编写一个APP，用户可以通过按地图在地图上删除图钉。引脚掉线后，我想将引脚保存到数据库中。我不关心哪一个可能与Realm或CoreData。

Answer 1

RTFM

没有任何代码或任何问题，无法真正帮助您。

一些可能有用的链接： https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/CoreData/index.html https://developer.apple.com/reference/corelocation https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/LocationAwarenessPG/Introduction/Introduction.html#//apple_ref/doc/uid/TP40009497

在你尝试之后回来;）

编辑：

您在viewDidLoad方法中定义了一个手势识别器，将其直接放在您的控制器中，这样可以删除一些错误：

import UIKit
import MapKit

class ViewController: UIViewController {

    @IBOutlet var mapView: MKMapView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Create a gesture recognizer for long presses (for example in viewDidLoad)
        UILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
        lpgr.minimumPressDuration = 0.5; //user needs to press for half a second.
        [self.mapView addGestureRecognizer:lpgr];
    }

    - (void)handleLongPress:(UIGestureRecognizer *)gestureRecognizer {
        if (gestureRecognizer.state != UIGestureRecognizerStateBegan) {
            return;
        }
        CGPoint touchPoint = [gestureRecognizer locationInView:self.mapView];
        CLLocationCoordinate2D touchMapCoordinate = [self.mapView convertPoint:touchPoint toCoordinateFromView:self.mapView];
        MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
        point.coordinate = touchMapCoordinate;
        for (id annotation in self.mapView.annotations) {
            [self.mapView removeAnnotation:annotation];
        }
        [self.mapView addAnnotation:point];
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

如何在地图视图上删除注释并保存引脚

1 个答案: