将mapview缩放到放置引脚的区域

如果我在mapview中有3个引脚，当地图加载时，我将如何缩放到这些引脚。 也就是说，当地图加载时我需要有一个缩放视图，但视图应该适应地图中掉落的所有引脚。 当地图只有一个引脚时，它正在工作。 但我不能用多个针脚处理缩放。 需要帮助

Answer 1

我在应用程序中编写了以下代码，它类似于@ElanthiraiyanS答案

-(void)zoomToFitMapAnnotations:(MKMapView*)mapView insideArray:(NSArray*)anAnnotationArray { // NSLog(@"%s", __FUNCTION__); if([mapView.annotations count] == 0) return; CLLocationCoordinate2D topLeftCoord; topLeftCoord.latitude = -90; topLeftCoord.longitude = 180; CLLocationCoordinate2D bottomRightCoord; bottomRightCoord.latitude = 90; bottomRightCoord.longitude = -180; for(MKPointAnnotation* annotation in anAnnotationArray) { 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 = [mapView regionThatFits:region]; [mapView setRegion:region animated:YES]; 

}

Answer 2

以下方法会这样做，

 - (void)zoomToFitMapAnnotations:(MKMapView *)mapView { if ([mapView.annotations count] == 0) return; CLLocationCoordinate2D topLeftCoord; topLeftCoord.latitude = -90; topLeftCoord.longitude = 180; CLLocationCoordinate2D bottomRightCoord; bottomRightCoord.latitude = 90; bottomRightCoord.longitude = -180; for(MapAnnotation *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 = [mapView regionThatFits:region]; [mapView setRegion:region animated:YES]; } 

Answer 3

你可以计算所有引脚的中心

 - (CLLocationCoordinate2D)centerPointFromAnnotationArray:(NSArray *)array { CLLocationCoordinate2D coorMax = CLLocationCoordinate2DMake(0, 0); CLLocationCoordinate2D coorMin = CLLocationCoordinate2DMake(999, 999); for ( int i = 0 ; i < [array count] ; ++i ) { LMPoint *a = [array objectAtIndex:i]; if ( ( a.coordinate.latitude != 0.0f ) || ( a.coordinate.longitude != 0.0f ) ) { if ( a.coordinate.latitude > coorMax.latitude ) { coorMax.latitude = a.coordinate.latitude; } if ( a.coordinate.longitude > coorMax.longitude ) { coorMax.longitude = a.coordinate.longitude; } if ( a.coordinate.latitude < coorMin.latitude ) { coorMin.latitude = a.coordinate.latitude; } if ( a.coordinate.longitude < coorMin.longitude ) { coorMin.longitude = a.coordinate.longitude; } } } CLLocationCoordinate2D coorCenter = CLLocationCoordinate2DMake((coorMax.latitude+coorMin.latitude)/2, (coorMax.longitude+coorMin.longitude)/2); return coorCenter; } 

然后使用适当的缩放级别缩放该点