#appdelegate

I just blogged: How to lock orientation at runtime on iOS 16 with .NET MAUI and Xamarin.Forms #iOS #iOS16 #iOSDev #dotNET #dotNETMAUI #XamarinForms #XamariniOS

The old way Before iOS 16, it was pretty easy to lock a Page into a certain orientation. It was basically just one line of code (if you don’t count the DependencyService boilerplate code in): UIDevice.CurrentDevice.SetValueForKey(new NSNumber((int)UIInterfaceOrientation.Portrait), new NSString("orientation")); By calling this method whenever the size of a page was allocated, we were able to…

Factory Design Pattern Illustration Overview AppDelegate or SceneDelegate is the main file that we as iOS developers know to configure, inject, or instantiate a global instance or frameworks. This place become essential, especially because it is actually the starting point of our app. Because it knows so many things, like configuring the frameworks, handling push notifications routing,…

original source : https://stackoverflow.com/questions/48723979/how-to-add-core-data-to-existing-xcode-9-swift-4-ios-11-project

프로젝트 시작시 core data 사용을 설정하지 않고 프로젝트를 진행하다가 나중에 core data를 사용하기로 결정한 경우에 대한 설명

best answer : https://stackoverflow.com/a/48724602/3151712

go to File > new file... select core Data under iOS and select Data Model you'll still need some code which xcode auto generates whenever you select core data during project creation. to get it, just create new project with core data option checked and copy all the code written under ** //Mark: - Core Data Stack** comment in AppDelegate.swift and add

import CoreData

above

OPTIONAL

오래전에 만들어진 tutorial이나 블로그 포스트를 보면 요즘(2018 6 10) 과 appdelegate에 있는 코드가 다른것을 알수 있다. 최근의 코드에서는 persistentContainer 를 통해 managedObjectContext, managedObjectModel, persistentStoreCoordinator 에 접근할수 있게 되었다.

최근)

// MARK: - Core Data stack lazy var persistentContainer: NSPersistentContainer = { /* The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. */ let container = NSPersistentContainer(name: "test") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { // Replace this implementation with code to handle the error appropriately. // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. /* Typical reasons for an error here include: * The parent directory does not exist, cannot be created, or disallows writing. * The persistent store is not accessible, due to permissions or data protection when the device is locked. * The device is out of space. * The store could not be migrated to the current model version. Check the error message to determine what the actual problem was. */ fatalError("Unresolved error \(error), \(error.userInfo)") } }) return container }() // MARK: - Core Data Saving support func saveContext () { let context = persistentContainer.viewContext if context.hasChanges { do { try context.save() } catch { // Replace this implementation with code to handle the error appropriately. // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. let nserror = error as NSError fatalError("Unresolved error \(nserror), \(nserror.userInfo)") } } }

예전)

アプリを作ったら必ずデフォルトでついてくるファイルの一つAppDelegate.swift 一体なにもの？ AppDelegate.swiftとは 　アプリ全体のライフタイムイベントを管理するためのクラス AppDelegate.swiftファイル内容 [swift] import UIKit @UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate { var window: UIWindow? func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { // Override point for…

When getting started with the CoreData framework, a common error you might run into when trying to test out your initial data model is:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Cannot create an NSPersistentStoreCoordinator with a nil model'

Clearly this isn't a very helpful exception. What do you mean nil model? I remember creating my model, how could it be nil?

The likely fix turns out to be painfully obvious. There may be a mismatch between the name of your object model file and the name being referenced in the managedObjectModel method.

First, open up the Project Navigator and check the name of the object model file. For example, let's say the object model file is named MyAppModel.xcdatamodelid. Now, we need to make sure that name corresponds to the name used in the App Delegate file.

Open up your app delegate file which is probably called something like XYZAppDelegate.m. Find the managedObjectModel method and check that the URLForResource argument in the following line of code matches your object model file name:

NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"MyAppModel" withExtension:@"momd"];

If this is where the mismatch was, try running your application again. If this wasn't where the problem was, then you might have to do a bit more searching.