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我一直在試圖將核心數據集成到以標準視圖控制器開始的故事板應用程序，但我正在遵循的教程使用標籤欄作爲初始視圖。核心數據應用程序在開始時崩潰
有沒有辦法用初始視圖控制器啓動應用程序，然後在應用程序委託中應用標籤欄？本教程使用應用程序委託來實現Core Data，並將標籤欄控制器用作初始視圖。
這裏是應用delegate.h
#import <UIKit/UIKit.h>
#import <CoreData/CoreData.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;
@property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
- (void)saveContext;
- (NSURL *)applicationDocumentsDirectory;
@end
，這裏是應用程序delegate.m文件
#import "AppDelegate.h"
#import "PersonsTVC.h"
#import "RolesTVC.h"
@implementation AppDelegate
@synthesize window = _window;
@synthesize managedObjectContext = __managedObjectContext;
@synthesize managedObjectModel = __managedObjectModel;
@synthesize persistentStoreCoordinator = __persistentStoreCoordinator;
@synthesize fetchedResultsController = __fetchedResultsController;
- (void)insertRoleWithRoleName:(NSString *)roleName
{
Role *role = [NSEntityDescription insertNewObjectForEntityForName:@"Role"
inManagedObjectContext:self.managedObjectContext];
role.name = roleName;
[self.managedObjectContext save:nil];
}
- (void)importCoreDataDefaultRoles {
NSLog(@"Importing Core Data Default Values for Roles...");
[self insertRoleWithRoleName:@"C/C++ Developer"];
[self insertRoleWithRoleName:@"Obj-C Developer"];
[self insertRoleWithRoleName:@"Java Developer"];
[self insertRoleWithRoleName:@"ASP.NET Developer"];
[self insertRoleWithRoleName:@"Unix Engineer"];
[self insertRoleWithRoleName:@"Windows Engineer"];
[self insertRoleWithRoleName:@"Business Analyst"];
[self insertRoleWithRoleName:@"Infrastructure Manager"];
[self insertRoleWithRoleName:@"Project Manager"];
[self insertRoleWithRoleName:@"Operations Manager"];
[self insertRoleWithRoleName:@"Desktop Support Analyst"];
[self insertRoleWithRoleName:@"Chief Information Officer"];
NSLog(@"Importing Core Data Default Values for Roles Completed!");
}
- (void)setupFetchedResultsController
{
// 1 - Decide what Entity you want
NSString *entityName = @"Role"; // Put your entity name here
NSLog(@"Setting up a Fetched Results Controller for the Entity named %@", entityName);
// 2 - Request that Entity
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:entityName];
// 3 - Filter it if you want
//request.predicate = [NSPredicate predicateWithFormat:@"Person.name = Blah"];
// 4 - Sort it if you want
request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"name"
ascending:YES
selector:@selector(localizedCaseInsensitiveCompare:)]];
// 5 - Fetch it
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request
managedObjectContext:self.managedObjectContext
sectionNameKeyPath:nil
cacheName:nil];
[self.fetchedResultsController performFetch:nil];
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self setupFetchedResultsController];
if (![[self.fetchedResultsController fetchedObjects] count] > 0) {
NSLog(@"!!!!! ~~> There's nothing in the database so defaults will be inserted");
[self importCoreDataDefaultRoles];
}
else {
NSLog(@"There's stuff in the database so skipping the import of default data");
}
// The Tab Bar
UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController;
// The Two Navigation Controllers attached to the Tab Bar (At Tab Bar Indexes 0 and 1)
UINavigationController *personsTVCnav = [[tabBarController viewControllers] objectAtIndex:0];
UINavigationController *rolesTVCnav = [[tabBarController viewControllers] objectAtIndex:1];
// The Persons Table View Controller (First Nav Controller Index 0)
PersonsTVC *personsTVC = [[personsTVCnav viewControllers] objectAtIndex:0];
personsTVC.managedObjectContext = self.managedObjectContext;
// The Roles Table View Controller (Second Nav Controller Index 0)
RolesTVC *rolesTVC = [[rolesTVCnav viewControllers] objectAtIndex:0];
rolesTVC.managedObjectContext = self.managedObjectContext;
//NOTE: Be very careful to change these indexes if you change the tab order
// Override point for customization after application launch.
// UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
// RolesTVC *controller = (RolesTVC *)navigationController.topViewController;
// controller.managedObjectContext = self.managedObjectContext;
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
/*
Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
*/
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
/*
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
*/
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
/*
Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
*/
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
/*
Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
*/
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Saves changes in the application's managed object context before the application terminates.
[self saveContext];
}
- (void)saveContext
{
NSError *error = nil;
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if (managedObjectContext != nil)
{
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&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.
*/
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}
#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 from the application's model.
*/
- (NSManagedObjectModel *)managedObjectModel
{
if (__managedObjectModel != nil)
{
return __managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"Model" withExtension:@"momd"];
__managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return __managedObjectModel;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (__persistentStoreCoordinator != nil)
{
return __persistentStoreCoordinator;
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"StaffManager.sqlite"];
NSError *error = nil;
__persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options 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.
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]);
abort();
}
return __persistentStoreCoordinator;
}
#pragma mark - Application's Documents directory
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
@end
正如你可以看到，我試圖將核心數據添加到我的故事板的應用。在這種情況下，在應用程序委託中，我將標籤欄控制器添加爲根視圖控制器，然後將控制器添加到標籤欄。
我喜歡在應用程序委託的標籤欄之前添加一個開始視圖，然後添加tabbar及其相應的控制器。
我試圖添加tabbar作爲子視圖，但託管對象不會被調用，應用程序崩潰。
如果更有經驗的程序員可以提供一些幫助，我真的很感激。如有必要，我可以通過電子郵件發送項目或上傳代碼。我需要指導傢伙，非常感謝我獲得的任何幫助。
什麼是崩潰時的確切錯誤信息？它到底在哪條線上發生？ – Anna 2012-08-30 03:05:16