将核心数据添加到现有的iPhone项目中

Question

我想将核心数据添加到现有的iPhone项目中，但我仍然遇到很多编译错误：

- NSManagedObjectContext undeclared

 - Expected specifier-qualifier-list before 'NSManagedObjectModel'

 - ...

我已经将核心数据框架添加到目标（右键单击我的项目“Targets”，“Add” - “Existing Frameworks”，“CoreData.framework”）。

我的头文件：

NSManagedObjectModel *managedObjectModel;

NSManagedObjectContext *managedObjectContext;       

NSPersistentStoreCoordinator *persistentStoreCoordinator;

[...]

@property (nonatomic, retain, readonly) NSManagedObjectModel *managedObjectModel;

@property (nonatomic, retain, readonly) NSManagedObjectContext *managedObjectContext;

@property (nonatomic, retain, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator;

我错过了什么？开始一个新项目不是一个选择......

非常感谢！

编辑 对不起，我确实有这些实现...但似乎缺少库...实现方法已满，编译错误如“ managedObjectContext undeclared”，“ NSPersistentStoreCoordinator undeclared”，但也有“预期”）'之前NSManagedObjectContext“（虽然它似乎括号是正确的）...

#pragma mark -

#pragma mark Core Data stack

/**

 Returns the managed object context for the application.

 If the context doesn't already exist, it is created and bound to the persistent store         

coordinator for the application.

 */

- (NSManagedObjectContext *) managedObjectContext {

    if (managedObjectContext != nil) {

        return managedObjectContext;

    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];

    if (coordinator != nil) {

        managedObjectContext = [[NSManagedObjectContext alloc] init];

        [managedObjectContext setPersistentStoreCoordinator: coordinator];

    }

    return managedObjectContext;

}

/**

 Returns the managed object model for the application.

 If the model doesn't already exist, it is created by merging all of the models found in    

 application bundle.

 */

- (NSManagedObjectModel *)managedObjectModel {

    if (managedObjectModel != nil) {

        return managedObjectModel;

    }

    managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];    

    return managedObjectModel;

}