沒有主數據的核心數據詳細模板

Question

我想創建一個使用核心數據的iphone應用程序。 據我所知，只有master-detail應用程序模板給了我一個使用Core Data的選項。但它創建了表格視圖。

我想使用的是視圖控制器不是表視圖控制器。 我不能使用單核視圖應用程序模板的核心數據。

我應該採用哪種方式來解決此問題？

謝謝。

Answer 1

你應該認識到，CoreData是一個框架，不綁定到像UITableView這樣的任何UIKit組件。您可以在任何類型的應用程序中自由使用它。您所要做的就是創建管理CoreData操作的單例類，並將CoreData.framework添加到您的項目中。

這裏是我的DataAccessLayer模板：

DataAccessLayer.h

#import <Foundation/Foundation.h> 
#import <CoreData/CoreData.h> 
@interface DataAccessLayer : NSObject 

@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext; 
@property (strong, nonatomic) NSManagedObjectModel *managedObjectModel; 
@property (strong, nonatomic) NSPersistentStoreCoordinator *storeCoordinator; 

+ (DataAccessLayer *)sharedInstance; 
- (void)saveContext; 

@end 

DataAccessLayer.m

#import "DataAccessLayer.h" 
@interface DataAccessLayer() 
- (NSURL *)applicationDocumentsDirectory; 
@end 

@implementation DataAccessLayer 
@synthesize storeCoordinator; 
@synthesize managedObjectModel; 
@synthesize managedObjectContext; 

+ (DataAccessLayer *)sharedInstance { 
    __strong static DataAccessLayer *sharedInstance = nil; 
    static dispatch_once_t onceToken; 
    dispatch_once(&onceToken, ^{ 
    sharedInstance = [[DataAccessLayer alloc] init]; 
    sharedInstance.storeCoordinator = [sharedInstance persistentStoreCoordinator]; 
    sharedInstance.managedObjectContext = [sharedInstance managedObjectContext]; 
    }); 
    return sharedInstance; 
} 

#pragma mark - Core Data 

- (void)saveContext { 
    @synchronized(self) { 
    NSError *error = nil; 
    if (managedObjectContext != nil) 
    { 
     if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) 
     { 
     NSLog(@"error: %@", error.userInfo); 
     /* 
     Replace this implementation with code to handle the error appropriately. 

     abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. 
     */ 
     NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Oops!" 
                 message:@"Something has gone terribly wrong! You need to reinstall the app in order for it to work properly." 
                 delegate:nil 
               cancelButtonTitle:@"Close." 
               otherButtonTitles:nil, nil]; 
     [alert show]; 
     } 
    } 
    } 
} 

#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; 
    } 

    if (storeCoordinator != nil) 
    { 
    managedObjectContext = [[NSManagedObjectContext alloc] init]; 
    [managedObjectContext setPersistentStoreCoordinator:storeCoordinator]; 
    } 
    return managedObjectContext; 
} 

/** 
Returns the managed object model for the application. 
If the model doesn't already exist, it is created from the application's model. 
*/ 
- (NSManagedObjectModel *)managedObjectModel { 
    if (managedObjectModel != nil) 
    { 
    return managedObjectModel; 
    } 
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"DataModel" withExtension:@"momd"]; 
    managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];  
    return managedObjectModel; 
} 

/** 
Returns the persistent store coordinator for the application. 
If the coordinator doesn't already exist, it is created and the application's store added to it. 
*/ 
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator { 
    if (storeCoordinator != nil) 
    { 
    return storeCoordinator; 
    } 

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"words_db.sqlite"]; 

    NSError *error = nil; 
    storeCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; 
    if (![storeCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) 
    { 
    /* 
    Replace this implementation with code to handle the error appropriately. 

    abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. 

    Typical reasons for an error here include: 
    * The persistent store is not accessible; 
    * The schema for the persistent store is incompatible with current managed object model. 
    Check the error message to determine what the actual problem was. 


    If the persistent store is not accessible, there is typically something wrong with the file path. Often, a file URL is pointing into the application's resources directory instead of a writeable directory. 

    If you encounter schema incompatibility errors during development, you can reduce their frequency by: 
    * Simply deleting the existing store: 
    [[NSFileManager defaultManager] removeItemAtURL:storeURL error:nil] 

    * Performing automatic lightweight migration by passing the following dictionary as the options parameter: 
    [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; 

    Lightweight migration will only work for a limited set of schema changes; consult "Core Data Model Versioning and Data Migration Programming Guide" for details. 

    */ 
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Oops!" 
                message:@"Something has gone terribly wrong! You need to reinstall the app in order for it to work properly." 
                delegate:nil 
              cancelButtonTitle:@"Close." 
              otherButtonTitles:nil, nil]; 
    [alert show]; 
    }  

    return storeCoordinator; 
} 

#pragma mark Application's Documents directory 

/** 
Returns the URL to the application's Documents directory. 
*/ 
- (NSURL *)applicationDocumentsDirectory { 
    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject]; 
} 


@end 

您還必須以創建自己的數據來創建一個.xcdatamodeld文件模型對象。並以適當

NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"DataModel" withExtension:@"momd"];