如何在不使用MKMapView的情况下检查MKCoordinateRegion是否包含CLLocationCoordinate2D？ [英] How to check if MKCoordinateRegion contains CLLocationCoordinate2D without using MKMapView?

问题描述

我需要检查用户位置是否属于MKCoordinateRegion。
我很惊讶没有为此找到简单的功能，类似于：CGRectContainsCGPoint（rect，point）。

I need to check if user location belongs to the MKCoordinateRegion. I was surprised not to find simple function for this, something like: CGRectContainsCGPoint(rect, point).

我发现以下一段代码：

CLLocationCoordinate2D topLeftCoordinate = 
    CLLocationCoordinate2DMake(region.center.latitude 
                               + (region.span.latitudeDelta/2.0), 
                               region.center.longitude 
                               - (region.span.longitudeDelta/2.0));


    CLLocationCoordinate2D bottomRightCoordinate = 
    CLLocationCoordinate2DMake(region.center.latitude 
                               - (region.span.latitudeDelta/2.0), 
                               region.center.longitude 
                               + (region.span.longitudeDelta/2.0));

        if (location.latitude < topLeftCoordinate.latitude || location.latitude > bottomRightCoordinate.latitude || location.longitude < bottomRightCoordinate.longitude || location.longitude > bottomRightCoordinate.longitude) {

    // Coordinate fits into the region

    }

但是，我不确定它是否准确，因为文档没有详细说明区域矩形的计算方式。

But, I am not sure if it is accurate as documentation does not specify exactly how the region rectangle is calculated.

必须有更简单的方法来做到这一点。我是否忽略了MapKit框架文档中的某些功能？

There must be simpler way to do it. Have I overlooked some function in the MapKit framework documentation?

推荐答案

如果还有其他人与纬度和长度相混淆，这里是经过测试的工作解决方案：

In case there is anybody else confused with latitudes and longitues, here is tested, working solution:

MKCoordinateRegion region = self.mapView.region;

CLLocationCoordinate2D location = user.gpsposition.coordinate;
CLLocationCoordinate2D center   = region.center;
CLLocationCoordinate2D northWestCorner, southEastCorner;

northWestCorner.latitude  = center.latitude  - (region.span.latitudeDelta  / 2.0);
northWestCorner.longitude = center.longitude - (region.span.longitudeDelta / 2.0);
southEastCorner.latitude  = center.latitude  + (region.span.latitudeDelta  / 2.0);
southEastCorner.longitude = center.longitude + (region.span.longitudeDelta / 2.0);

if (
    location.latitude  >= northWestCorner.latitude && 
    location.latitude  <= southEastCorner.latitude &&

    location.longitude >= northWestCorner.longitude && 
    location.longitude <= southEastCorner.longitude
    )
{
    // User location (location) in the region - OK :-)
    NSLog(@"Center (%f, %f) span (%f, %f) user: (%f, %f)| IN!", region.center.latitude, region.center.longitude, region.span.latitudeDelta, region.span.longitudeDelta, location.latitude, location.longitude);

}else {

    // User location (location) out of the region - NOT ok :-(
    NSLog(@"Center (%f, %f) span (%f, %f) user: (%f, %f)| OUT!", region.center.latitude, region.center.longitude, region.span.latitudeDelta, region.span.longitudeDelta, location.latitude, location.longitude);
}

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