如何在MKMapView中获得更精细的跨度 [英] How can I get a finer grained span in my MKMapView

问题描述

我正在使用MKMapView并且我正在初始化如下：

I'm using an MKMapView and I'm initializing like this:

homeLocation.latitude = 42.033126;
homeLocation.longitude = -70.168621;

[self.mapView setCenterCoordinate:homeLocation animated:NO];

MKCoordinateRegion viewRegion;

viewRegion.center = homeLocation;
viewRegion.span = MKCoordinateSpanMake(1.7, 1.7);

[self.mapView setRegion:[self.mapView regionThatFits:viewRegion] animated:NO];

这是我的应用

< img src =https://i.stack.imgur.com/c3BLp.jpgalt =在此处输入图像说明>

这很好，除了我的app我需要将它缩小一点。但是当我尝试这个时：

That's fine, except for my app I need to have it zoomed out a tiny bit more. But when I try this:

viewRegion.span = MKCoordinateSpanMake(1.8, 1.8);   // use span of 1.8, not 1.7

我明白了：

它缩小了出路。如果我查看MKMapView的区域，latitudeDelta i 3.54981和longitudeDelta是3.51562。

It is zoomed way out. If I look at the MKMapView's region the latitudeDelta i 3.54981 and the longitudeDelta is 3.51562.

如何将我的跨度设置为1.7到3.5之间的值？我希望这个特定的应用程序能够达到2.25左右。

How can I set my span to a value between 1.7 and 3.5? I'd love to hit around 2.25 for this particular application.

注意：mapview捏缩放到任何我想要的范围都可以。

NOTE: the mapview pinch zooms just fine to whatever span I want.

推荐答案

MKCoordinateSpanMake使用度数，1度约69英里。如果你想要更细粒度的设置，请改用MKCoordinateRegionMakeWithDistance。

MKCoordinateSpanMake uses degrees, and 1 degree is about 69 miles. If you want a more fine grained setting, use MKCoordinateRegionMakeWithDistance instead.

CLLocationCoordinate2D homeLocation;
homeLocation.latitude = 42.033126;
homeLocation.longitude = -70.168621;

[self.mapView setCenterCoordinate:homeLocation animated:NO];

 MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance( homeLocation, 200000, 200000);
// 200000 meter is approximately 1.8 degree
[self.mapView setRegion:[self.mapView regionThatFits:viewRegion] animated:NO];

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