Can you show please how I can add UITextView in your annotation?
oh, you’re posting in the old version of this tutorial?
the most recent version is https://www.raywenderlich.com/160517/mapkit-tutorial-getting-started
It has a section Custom Callout Accessory Views with code to customise the detail accessory (where the subject is displayed):
let detailLabel = UILabel()
detailLabel.numberOfLines = 0
detailLabel.font = detailLabel.font.withSize(12)
detailLabel.text = artwork.subtitle
detailCalloutAccessoryView = detailLabel
the tutorial is Swift 4 etc but the code above works in Swift 3/Xcode 8.
So instead of UILabel, make it a UITextview