No managedObjectContext defined in my AppDelegate

问题

I'm trying to test my core data scheme. However, it seems I am unable to create the context because it says No visible @interface for 'MyAppDelegate' declares the selector 'managedObjectContext'.

In online tutorials this method seems to be auto-generated when we create the app. However, in my case it doesn't exist.

This is MyAppDelegate:

Header

#import <UIKit/UIKit.h>


@interface MyAppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@end

.m file

#import "MyAppDelegate.h"


@implementation MyAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    NSManagedObjectContext *context = [self managedObjectContext];
    // Override point for customization after application launch.
    return YES;
}

How should I fix this in Xcode 5 with iOS 7?

回答1:

I think the best way for you is to create a Master-Detail Application with Xcode 5 and don't forget to check Use Core Data :

With that, you will have an AppDelegate.h and an AppDelegate.m configured with a managedObjectContext.

You will have a project configured correctly with Core Data and a .xcdatamodeld to use easily your SQLite database.

来源：https://stackoverflow.com/questions/19432058/no-managedobjectcontext-defined-in-my-appdelegate