CODEWITHSUNDEEP
iphoneobjective-ccore-data
JackieLam
JackieLam

Reputation: 668

Fail to manage Core Data in Models other than AppDelegate.m

- (void)doneButtonPressed
{
    //判断已存在这个title的proj的话不创建

    //存储CD数据
    Project *newProject = [NSEntityDescription insertNewObjectForEntityForName:@"Project" inManagedObjectContext:self.managedObjectContext];
    //!!!!crash here!!!!
    newProject.title = self.titleTextField.text;
    newProject.subtitle = self.subtitleTextField.text;
    newProject.progress = [NSNumber numberWithFloat:1.0f];
    newProject.pid = @"001";

    NSError* savingError = nil;
    if (newProject != nil){
        if ([self.managedObjectContext save:&savingError]){
            NSLog(@"Saved!");
        }
        else{
            NSLog(@"Fail to save the proj");
        }
    }
    else{
        NSLog(@"Fail to create new proj");
    }
}

I simply add these code into my CertainViewController.m and found that I could not save things into the core data.

Here below shows the reason:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name 'Project''

Do I miss some pre-setting in the CertainViewController?

@property (nonatomic, strong) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, strong) NSEntityDescription *entityDescription;

I do include these two property into the .h and synthesize them in the .m.

Will really appreciate your answer;)

Upvotes: 0

Views: 64

Answers (2)

Dan Shelly
Dan Shelly

Reputation: 6011

The answer is simple. you have not set your context properly.

If i guess correctly (and I do cause I tested it), you have only alloc init your context like so:
self.managedObjectContext = [[NSManagedObjectContext] alloc] init];

A context defined like this is orphaned as it does not have a NSPersistentStoreCoordinator or parentContext to get to the persistent store from.

You should either pass the context from the previous view controller, or set it up yourself:

//Example:
AppDelegate* delegate = (AppDelegate*)[[UIApplication sharedApplication] delegate];
self.managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:<#(NSManagedObjectContextConcurrencyType)#>];
[self.managedObjectContext setPersistentStoreCoordinator:delegate.persistentStoreCoordinator];

Upvotes: 1

user1025285
user1025285

Reputation:

Check the following steps:

  1. Try delete app from simulator or Device after run

  2. Check the below tutorials, http://www.raywenderlich.com/934/core-data-on-ios-5-tutorial-getting-started http://mobile.tutsplus.com/tutorials/iphone/iphone-core-data/

Upvotes: 0

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