我有一个自定义类来扩展NSObject并实现MKOverlay协议.因此,我需要实现一个MKMapRect协议的boundingMapRect属性.为了创建一个MKMapRect,我当然可以使用MKMapRectMake做一个.但是,我不知道如何使用这个数据创建一个MKMapRect,它是两点,每一个都由纬度和纬度指定. MKMapRectMake的文档状态：

MKMapRect MKMapRectMake(
    double x,double y,double width,double height
);

Parameters
x
    The point along the east-west axis of the map projection to use for the origin.
y
    The point along the north-south axis of the map projection to use for the origin.
width
    The width of the rectangle (measured using map points).
height
    The height of the rectangle (measured using map points).
Return Value
    A map rectangle with the specified values.

经纬度值我必须指出MKMapRect是：

24.7433195,-124.7844079
49.3457868,-66.9513812

因此,目标MKMapRect需要指定一个如下所示的区域：

所以,要重申一下,如何使用我的lat / lon值创建一个MKMapRect,我可以设置为MKOverlay协议的@property(非原子,只读)MKMapRect boundingMapRect属性？提前感谢您能够提供的任何帮助！谢谢！！

// these are your two lat/long coordinates
CLLocationCoordinate2D coordinate1 = CLLocationCoordinate2DMake(lat1,long1);
CLLocationCoordinate2D coordinate2 = CLLocationCoordinate2DMake(lat2,long2);

// convert them to MKMapPoint
MKMapPoint p1 = MKMapPointForCoordinate (coordinate1);
MKMapPoint p2 = MKMapPointForCoordinate (coordinate2);

// and make a MKMapRect using mins and spans
MKMapRect mapRect = MKMapRectMake(fmin(p1.x,p2.x),fmin(p1.y,p2.y),fabs(p1.x-p2.x),fabs(p1.y-p2.y));