Question

如何向viewRegion.span.latitudeDelta添加2英里？我该如何计算kTwoMiles？

MKCoordinateRegion viewRegion;
viewRegion.center = coordinateCentre;
viewRegion.span.latitudeDelta = latitudeMax - latitudeMin + kTwoMiles;  
viewRegion.span.longitudeDelta = longitudeMax - longitudeMin + kTwoMiles;

MKCoordinateRegion adjustedRegion = [mapView regionThatFits:viewRegion];
[mapView setRegion:adjustedRegion animated:YES];

Answer 1

基本上这是相对复杂的，因为每个学位都有不同的三角形在地球赤道，你将有每度111公里和0公里的极点。（http://en.wikipedia.org/wiki/Longitude#Degree_length）

Answer 2

我决定只在纬度德尔塔增加2英里。可能是regionFhatFits将调整经度Delta的大小。

double kTwoMiles = (double)2/69; 
MKCoordinateRegion viewRegion;
viewRegion.center = coordinateCentre;
viewRegion.span.latitudeDelta = latitudeMax - latitudeMin + kTwoMiles;  
viewRegion.span.longitudeDelta = longitudeMax - longitudeMin;

MKCoordinateRegion adjustedRegion = [mapView regionThatFits:viewRegion];
[mapView setRegion:adjustedRegion animated:YES];`enter code here`

如何在viewRegion.span.latitudeDelta上添加2英里？

2 个答案: