iOS Components and Frameworks: Understanding the Advanced Features of the iOS SDK

Map Annotations and Overlays

A map view (MKMapView) is a scroll view that behaves specially; adding a subview to it in the standard way will not add the subview to the scrollable part of the map view, but rather the subview will remain static relative to the frame of the map view. Although that might be a feature for items like hovering buttons or labels, being able to identify and mark points and details on the map is a key feature. Map annotations and overlays are a way to mark items or areas of interest in a map view. Annotations and overlays maintain their position on a map as the map is scrolled and zoomed. Map annotations are defined by a single coordinate point on the map, and map overlays can be lines, polygons, or complex shapes. MapKit ...