获取NSInternalInconsistencyException错误！

Question

我收到错误：

  

***由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'+ entityForName：无法找到实体名称的NSManagedObjectModel'练习''

行：Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

（您可以在此处查看我的数据模型：How is This Data Model?）。 有什么想法吗？

   - (void)viewDidLoad
    {
        [super viewDidLoad];

        UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
        self.navigationItem.rightBarButtonItem = addButton;
        [addButton release];

        //if (managedObjectContext == nil) 
        { 
            managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        }

        NSFetchRequest *request = [[NSFetchRequest alloc] init];
        NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
        [request setEntity:entity];

        NSLog(@"After managedObjectContext: %@",  managedObjectContext);


        NSError *error = nil;
        NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
        if (mutableFetchResults == nil) {
            // Handle the error.
        }
        [mutableFetchResults release];
        [request release];
    }

    -(IBAction)exerciseChooser
    {
        RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];

        [self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
    }

    -(void)addExercise
    {    
        Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

        exercise.name=@"Test";

        NSError *error = nil;
        if (![managedObjectContext save:&error]) 
        {
            // Handle the error.
        }
        NSLog(@"%@", error);

        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];

        NSInteger lastSection = [self.tableView numberOfSections] -1;

        [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.tableView numberOfRowsInSection:lastSection]-1 inSection:lastSection] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
    }

Answer 1

此错误只有几个可能的来源：

1. 实体名称中的错字。
2. 无管理对象上下文对象。
3. 未能将包含实体的模型添加到上下文使用的持久性存储中。
4. 未能将正确的持久存储添加到上下文本身。

请参阅上一个问题：

insertNewObjectForEntityForName:

<强>更新

为什么if语句被注释掉了？

if(managedObjectContext == nil) 

我认为这是必需的。

修改

-(void)addExercise
{    
    if(managedObjectContext!=nil)
    {
        Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

        exercise.name=@"Test";

        NSError *error = nil;
        if (![managedObjectContext save:&error]) 
        {
            // Handle the error.
        }
        NSLog(@"%@", error);

        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];

        NSInteger lastSection = [self.tableView numberOfSections] -1;

        [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.tableView numberOfRowsInSection:lastSection]-1 inSection:lastSection] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
    }
}