更新位置时的地图视图范围更改

我在视图控制器中有一个函数，它具有当位置更改时调用的mapkit。我想设置为地图视图，以便以当前位置为中心并在更新时随其移动。更新位置时的地图视图范围更改

它在某种意义上说起作用，即它可以跟踪，但它始终在放大真的很远。如果我缩小了它对齐回到它在获取新位置后再次调用更新的位置。

in from params CLLocation *loc 
bool first = TRUE; 
if(first){ 
     first=FALSE; // bit of a bodge...if i set this to false it will track the update possition but not at the desired "zoom" its look far to close. 
     CLLocation *loc = [[CLLocation alloc] initWithLatitude:54.976619 longitude:-1.613118];//newcastle city center. 
     CLLocationDegrees spanLat = 1000; 
     CLLocationDegrees spanLng = 1000; 
     userLocation = MKCoordinateRegionMakeWithDistance(loc.coordinate, spanLat, spanLng); 
     [mapview setRegion:userLocation animated:TRUE]; 
    }else { 
     CLLocationDegrees spanLat = [mapview region].span.latitudeDelta;// keep the originals? DOESN'T WORK!! 
     CLLocationDegrees spanLng = [mapview region].span.longitudeDelta;// 
     userLocation = MKCoordinateRegionMakeWithDistance(loc.coordinate, spanLat, spanLng); 
     [mapview setRegion:userLocation animated:TRUE]; 
    }

来源

2013-03-29 Andrew