The area currently displayed by the map view.
- iOS 3.0+
- macOS 10.9+
- tvOS 9.2+
The region encompasses both the latitude and longitude point on which the map is centered and the span of coordinates to display. The span values provide an implicit zoom value for the map. The larger the displayed area, the lower the amount of zoom. Similarly, the smaller the displayed area, the greater the amount of zoom.
Changing only the center coordinate of the region can still cause the span to change implicitly. The span might change because the distances represented by a span change at different latitudes and longitudes and the map view may need to adjust the span to account for the new location. If you want to change the center coordinate without changing the zoom level, use the
Changing the value of this property updates the map view immediately. When setting this property, the map may adjust the new region value so that it fits the visible area of the map precisely. This is normal and is done to ensure that the value in this property always reflects the visible portion of the map. However, it does mean that if you get the value of this property right after setting it, the returned value may not match the value you set. (You can use the
region method to determine the region that will actually be set by the map.)
If you want to animate the change in region, use the
set method instead.