MapView regionThatFits使用horizo​​ntalAccuracy设置

Question

我正在寻找一种将米转换为mapview区域的方法。

CLLocation的{​​{1}}是一个双精度数，表示以米为单位的精确度。 horizontalAccuracy会regionThatFits: MKCoordinateRegion span和longitudeDelta。如何将米转换为经度/纬度范围？

Answer 1

找到答案。似乎1度纬度等于111公里左右，或111120米

- (MKCoordinateRegion)regionForAccuracyOfLocation:(CLLocation *)location
{
    CLLocationDegrees spanInDegrees = (CLLocationDegrees) (location.horizontalAccuracy / 222240);

    MKCoordinateSpan span = MKCoordinateSpanMake(spanInDegrees, spanInDegrees) ;
    CLLocationCoordinate2D coordinate = location.coordinate;
    MKCoordinateRegion region = MKCoordinateRegionMake(coordinate, span);

    return region;
}