Cfrgtkky

I have an MKMapView taking up the entire screen above the tab-bar.

On top of the map, I have added another overlay UIView which draws a dot in the center of the view. The constraints of the overlay are set to match the top, bottom, leading and trailing anchors of the map view.

But when I move the map view around, the reported center position of the map view is not the position below the dot in the center of the overlay.

To make it align, I have to apply -8 pt constant to the top and bottom constraints.

I tried looking into margins, insets etc of the map view but found nothing that looked like the number 8 on the Y axis.

let overlayYoffset: CGFloat = -8

NSLayoutConstraint.activate([

    view.overlayView.topAnchor.constraint(equalTo: mapView.topAnchor, constant: overlayYoffset),

    view.overlayView.bottomAnchor.constraint(equalTo: mapView.bottomAnchor, constant: overlayYoffset),

Debugging the view hierarchy also shows that the overlay view and the map view has the same size and positions on top of each other.

So what is causing this issue? Have I overlooked anything, or is it "by design" that the MKMapview is not showing its centerCoordinate in the exact center of its view?

Regarding top you may need +8 instead of -8

view.overlayView.topAnchor.constraint(equalTo: mapView.topAnchor, constant: -1 * overlayYoffset)