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[英]How to zoom in and zoom out MKCircle in MKMapView on the same button click in ios?
[英]How to calculate the zoom level of MKMapView to fit MKCircle?
我想在按钮单击事件中显示 mkcircle。我必须使用圆半径计算 MKMapView 的缩放级别以使圆引人注目。让半径可以是任何大小,但 mkmapview 上的 mkcircle 应该足够大,如截图所示。我的代码:
- (IBAction)showCircle:(id)sender {
long radius=[self calculateRadius];
NSLog(@"draw circle of radius=%ld",radius);
MKCircle *circle= [[MKCircle alloc]init];
circle = [MKCircle circleWithCenterCoordinate:CLLocationCoordinate2DMake([groupLat floatValue], [groupLon floatValue]) radius:radius];
[myMapView addOverlay:circle];
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(CLLocationCoordinate2DMake([groupLat floatValue], [groupLon floatValue]), 800, 800);
//calculate zoom level
double radius = [circle radius] + [circle radius] / 2;
double scale = radius / 500;
zoomLevel=(16 - log(scale) / log(2));
region.span.latitudeDelta =zoomLevel;
region.span.longitudeDelta =zoomLevel;
[myMapView setRegion:region animated:YES];
//问题是圆看起来很小,外面的空间更大
任何建议,将不胜感激。 谢谢你!
我知道它的旧帖子,但以任何方式回复.. Swift 5 中的代码,Xcode 11
let region = MKCoordinateRegion(circle.boundingMapRect)
mapView.setRegion(region, animated: true)
或者我们可以通过以下方式轻松添加一些边距
mapView.setVisibleMapRect(circle.boundingMapRect, edgePadding: UIEdgeInsets(top: 50, left: 50, bottom: 50, right: 50), animated: true)
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