Value of type AppDelegate has no member managedObjectContext in swift 4

please use below code

import CoreData frame work
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    let appDel:AppDelegate = UIApplication.shared.delegate as! AppDelegate
    let context:NSManagedObjectContext = appDel.persistentContainer.viewContext

    return true
}