显示MKMapView以一次显示多个注释和当前用户位置

Question

我在MKMapView上显示了多个注释，但是当我想用多个注释显示当前用户位置时，它跳转到用户位置并且不显示全部注释和用户位置在同一屏幕上。

Answer 1

您好，您必须根据地图区域中的注释坐标设置地图视图。

-(void)zoomToFitMapAnnotations:(MKMapView*)mapView 
{ 
if([self.mapView.annotations count] == 0) 
    return; 

CLLocationCoordinate2D topLeftCoord; 
topLeftCoord.latitude = -90; 
topLeftCoord.longitude = 180; 

CLLocationCoordinate2D bottomRightCoord; 
bottomRightCoord.latitude = 90; 
bottomRightCoord.longitude = -180; 

for(DDAnnotation* annotation in mapView.annotations) 
{ 
    topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude); 
    topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);   
    bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude); 
    bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude); 
} 

MKCoordinateRegion region; 
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5; 
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5; 
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides 
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides 

region = [self.mapView regionThatFits:region]; 
[self.mapView setRegion:region animated:YES]; 
} 

Answer 2

您需要设置根据两个引脚您的MapView的区域 -

float maxLat = current_location_latitude; 
float maxLon = current_location_longitude; 
float minLat = other_location_latitude; 
float minLon = other_location_longitude; 

MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(CLLocationCoordinate2DMake((maxLat + minLat)/2.0, (maxLon + minLon)/2.0), 1000.0, 1000.0); 
region.span.latitudeDelta = MAX(region.span.latitudeDelta, (maxLat - minLat) * 1.20); 
region.span.longitudeDelta = MAX(region.span.longitudeDelta, (maxLon - minLon) * 1.20); 
[self.mapView setRegion:region animated:YES];