我想將核心數(shù)據(jù)添加到現(xiàn)有的iPhone項目中，但我仍然遇到很多編譯錯誤：- NSManagedObjectContext undeclared - Expected specifier-qualifier-list before 'NSManagedObjectModel' - ...我已經(jīng)將核心數(shù)據(jù)框架添加到目標(biāo)（右鍵單擊我的項目“Targets”，“Add” - “Existing Frameworks”，“CoreData.framework”）。我的頭文件：NSManagedObjectModel *managedObjectModel;NSManagedObjectContext *managedObjectContext;       NSPersistentStoreCoordinator *persistentStoreCoordinator;[...]@property (nonatomic, retain, readonly) NSManagedObjectModel *managedObjectModel;@property (nonatomic, retain, readonly) NSManagedObjectContext *managedObjectContext;@property (nonatomic, retain, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator;我錯過了什么？開始一個新項目不是一個選擇......非常感謝！編輯 對不起，我確實有這些實現(xiàn)...但似乎缺少庫...實現(xiàn)方法已滿，編譯錯誤如“ managedObjectContext undeclared”，“ NSPersistentStoreCoordinator undeclared”，但也有“預(yù)期”）'之前NSManagedObjectContext“（雖然它似乎括號是正確的）...#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;}