WKInterfaceMap sometimes renders blank in a very simple app I am developing. The map appears completely empty (no grid of lines or anything similar). It looks as though the thread responsible for drawing the tiles gets blocked.
In order to reproduce the issue just add the code below to the extension delegate.
func applicationDidEnterBackground() {
let watchExtension = WKExtension.shared()
// Schedule the background refresh task.
watchExtension.scheduleBackgroundRefresh(withPreferredDate: Date().addingTimeInterval(15.0*60.0), userInfo: nil) { (error) in
// Check for errors.
if let error = error {
print("ExtensionDelegate: \(error.localizedDescription)")
return
}
print("ExtensionDelegate: Background Task scheduled successfuly")
}
}
Add a WKInterfaceMap to the main view and run once on the simulator. Close the app using the crown and stop it from XCode. Wait for at least 15 minutes and open the app again directly from the simulator.
The map renders then as in the image below.
