Question

我是初学者，我有2个坐标变量，当他们办理入住手续并在我的应用中结账时，可以根据用户位置动态更改。

获得这两个坐标后，我将使用此函数向地图工具包中添加注释。

func addMapAnnotation(coordinate: Coordinate, color: UIColor) {
        let span : MKCoordinateSpan = MKCoordinateSpanMake(0.0005, 0.0005)
        let location : CLLocationCoordinate2D = CLLocationCoordinate2DMake(coordinate.latitude, coordinate.longitude)
        let region : MKCoordinateRegion = MKCoordinateRegionMake(location, span)
        mapKitView.setRegion(region, animated: true)

        let annotation = MyPointAnnotation()
        annotation.coordinate = CLLocationCoordinate2D(latitude: coordinate.latitude, longitude: coordinate.longitude)
        annotation.pinTintColor = color
        mapKitView.addAnnotation(annotation)
    }

因为我设置了跨度和区域，并且2个坐标是动态的（即这两个坐标之间的距离可以是1公里，或者它可以是5公里，10公里等等），所以会有一个当视图控制器第一次出现时，其中一个注释没有直接显示的可能性，我必须先缩小才能看到第二个注释。

我想要的是，我想根据2个坐标的距离动态设置Map Kit跨度和区域，这样用户就不必缩小以查看两个注释

你能帮我分享一下代码吗？提前谢谢。

Answer 1

Sh_Khan的回答很好，尽管有些过时了。这是为Swift 5更新的扩展程序

extension MKCoordinateRegion {
    init(coordinates: [CLLocationCoordinate2D], spanMultiplier: CLLocationDistance = 1.8) {
        var topLeftCoord = CLLocationCoordinate2D(latitude: -90, longitude: 180)
        var bottomRightCoord = CLLocationCoordinate2D(latitude: 90, longitude: -180)

        for coordinate in coordinates {
            topLeftCoord.longitude = min(topLeftCoord.longitude, coordinate.longitude)
            topLeftCoord.latitude = max(topLeftCoord.latitude, coordinate.latitude)

            bottomRightCoord.longitude = max(bottomRightCoord.longitude, coordinate.longitude)
            bottomRightCoord.latitude = min(bottomRightCoord.latitude, coordinate.latitude)
        }

        let cent = CLLocationCoordinate2D.init(latitude: topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5, longitude: topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5)
        let span = MKCoordinateSpan.init(latitudeDelta: abs(topLeftCoord.latitude - bottomRightCoord.latitude) * spanMultiplier, longitudeDelta: abs(bottomRightCoord.longitude - topLeftCoord.longitude) * spanMultiplier)

        self.init(center: cent, span: span)
    }
}

根据需要修改spanMultiplier

Answer 2

调用此功能可缩小并显示所有注释

func zoomToFitMapAnnotations(aMapView:MKMapView)
{
    if(aMapView.annotations.count == 0)
    {
          return
    }


    var topLeftCoord = CLLocationCoordinate2D.init(latitude: -90, longitude: 180)


    var bottomRightCoord = CLLocationCoordinate2D.init(latitude: 90, longitude: -180)


    for i in 0..<myMapView.annotations.count
    {
        let annotation = myMapView.annotations[i]

        topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
        topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);

        bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
        bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
    }


    let resd = CLLocationCoordinate2D.init(latitude: topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5, longitude: topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5)

    let span = MKCoordinateSpan.init(latitudeDelta: fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.3, longitudeDelta: fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.3)

    var region = MKCoordinateRegion.init(center: resd, span: span);



    region = aMapView.regionThatFits(region)

    aMapView.setRegion(region, animated: true)


}

如何设置地图套件范围和与2坐标距离相关的区域？

2 个答案: