将视点转换为MKMapView坐标 [英] Converting View Points to MKMapView Coordinates

问题描述

我的目标是将视图的左上角和右下角转换为纬度/经度坐标。这些lat / lon坐标将用于查询仅存在于视图中的注释位置（不是全部5000 +）。

My objective is to convert the top left and bottom right points of my view to lat/lon coordinates. These lat/lon coordinates will be used to query annotation locations that only exist within the view (not all 5000+).

我发现这个目标 - Stackoverflow上的C提示。但我遇到的问题是它从mapView转换0,0（纬度/经度为-180，-180.Aka，南极）。

I found this Objective-C tip on Stackoverflow. But the issue I have is that it is converting 0,0 from the mapView (a lat/lon of -180,-180. Aka, the Southpole).

所以而不是：

topLeft = mapView.convertPoint(CGPointMake(0, 0), toCoordinateFromView: self.mapView)

我想我可以这样做：

topLeft = view.convertPoint(CGPointMake(0, 0), toCoordinateFromView: self.mapView)

但我收到错误：

无法使用类型'的参数列表调用'convertPoint'（CGPoint，
toCoordinateFromView：MKMapView！）'

Cannot invoke 'convertPoint' with an argument list of type '(CGPoint, toCoordinateFromView: MKMapView!)'

我花了一天的时间试图弄明白，但无济于事，我来了给你寻求指导。任何帮助将不胜感激。

I have spent a day trying to figure it out, but to no avail, and I have come to you seeking guidance. Any help would be much appreciated.

这是完整的功能：

func findCornerLocations(){

    var topLeft = CLLocationCoordinate2D()
    let mapView = MKMapView()
    topLeft = view.convertPoint(CGPointMake(0, 0), toCoordinateFromView: self.mapView)

    print(topLeft.latitude, topLeft.longitude)
}

推荐答案

你非常非常接近！

let topLeft = map.convertPoint(CGPointMake(0, 0), toCoordinateFromView: self.view)
let bottomleft = map.convertPoint(CGPointMake(0, self.view.frame.size.height), toCoordinateFromView: self.view)

实现时，它看起来像这样：

When implemented, it'll look like this:

        let map = MKMapView()
        map.frame = CGRectMake(100, 100, 100, 100)
        let coord = CLLocationCoordinate2DMake(37, -122)
        let span = MKCoordinateSpanMake(1, 1)
        map.region = MKCoordinateRegionMake(coord, span)
        self.view.addSubview(map)

        let topleft = map.convertPoint(CGPointMake(0, 0), toCoordinateFromView: self.view)
        let bottomleft = map.convertPoint(CGPointMake(0, self.view.frame.size.height), toCoordinateFromView: self.view)

        print("top left = \(topleft)")
        print("bottom left = \(bottomleft)")

这篇关于将视点转换为MKMapView坐标的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！