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;
}