更新位置時的地圖視圖範圍更改

我在視圖控制器中有一個函數，它具有當位置更改時調用的mapkit。我想設置爲地圖視圖，以便以當前位置爲中心並在更新時隨其移動。更新位置時的地圖視圖範圍更改

它在某種意義上說起作用，即它可以跟蹤，但它始終在放大真的很遠。如果我縮小了它對齊回到它在獲取新位置後再次調用更新的位置。

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]; 
    }

來源

2013-03-29 Andrew