NS管理上下文线程

本文介绍了NS管理上下文线程的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我使用单例来处理数组等，跨越应用程序中的视图。

I use a singleton for working with arrays etc. cross the views in the application.

要初始化单例和 NSManagedObjectContext ，以便我可以获取对象，我使用：

To initialize the singleton and the NSManagedObjectContext, so that I can fetch objects, I use:

+(DataControllerSingleton *)singleDataController { static DataControllerSingleton * single=nil; @synchronized(self) { if(!single) { single = [[DataControllerSingleton alloc] init]; NSManagedObjectContext *context = [single.fetchedResultsController managedObjectContext]; single.masterCareList = [[NSMutableArray alloc] init]; } } return single; }

当我插入一个新对象时，对象不会显示在显示函数中，直到我重新启动应用程序。我通过这个方法在单例类中插入新对象：

When I insert a new object that object will not show up in display functions until I restart the application. I insert new object through this method in the singleton class:

- (void)insertNewObject:(Care *)care { NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity]; NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName: [entity name] inManagedObjectContext:self.managedObjectContext]; NSString *fileName = care.pictureURL; NSString *text = care.causeText; NSDate *date = care.date; NSData *imgData = care.imageData; [newManagedObject setValue:fileName forKey:@"urlPath"]; [newManagedObject setValue:text forKey:@"name"]; [newManagedObject setValue:date forKey:@"date"]; [newManagedObject setValue:imgData forKey:@"imageData"]; // Save the context. [self saveContext]; NSError *error = nil; if (![context 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(); } }

我的计数方法是我可以告诉新对象不包括在内，直到我重新启动应用程序。 count方法也在singleton中。

My count method is the way I can tell that the new object is not included until I restart the application. The count method is also in the singleton as well.

- (NSUInteger)countOfList { NSArray *fetchedData = [_fetchedResultsController fetchedObjects]; return [fetchedData count]; }

当调用singleton时，我使用：

When calling singleton I use:

DataControllerSingleton *singletonData = [DataControllerSingleton singleDataController]; [singletonData insertNewObject:care];

managedObjectContext 属性：

.h：

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

.m：

@implementation DataControllerSingleton @synthesize managedObjectContext = _managedObjectContext; @synthesize managedObjectModel = _managedObjectModel; @synthesize persistentStoreCoordinator = _persistentStoreCoordinator;

为什么在重新启动应用程序之前我的新对象不会显示

Why will not my new object show up in ex count until I restart application?

我不知道如何使用不同的线程与不同的上下文，或不同的fethedResultsController或不同的单例（不应该是可能的？）

Am I somehow using different threads with different contexts, or different fethedResultsController or different singleton (shouldnt be possible right?)??

我添加了这两行，它们不包括在生成的CoreData堆栈中，现在可以正常工作。

I added these two lines, which are not included in the genereated CoreData Stack, and it now works fine.

在单例标题中：

@interface DataControllerSingleton : NSObject <NSFetchedResultsControllerDelegate>

在实施文件中，

(NSFetchedResultsController *)fetchedResultsController { _fetchedResultsController.delegate = self;

推荐答案

表格等。

如果您想在保存上下文时更新表格，您需要：

If you want to update the table as soon as you save the context you need to:

重新载入数据表 [table reloadData];

（请参阅如何使用NSFetchedResultsController ）

Reload the data table [table reloadData];

or implement in the correct delegate methods of (take a look to How To Use NSFetchedResultsController)

如果您遵循第一个选项，您只需在上下文中执行保存并调用表上的realod数据。

If you follow the first option, you can just do a save in the context and call realod data on the table.

NSError *error = nil; if (![context 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(); } [table reloadData];

请注意，您正在致电保存两次。在这种情况下，我假设 [self saveContext]; 执行如上保存。

NOTE THAT YOU ARE CALLING THE SAVE TWICE Do it once. In this case I suppose that [self saveContext]; does the saving as above.

希望有帮助。

编辑

您获取的结果控制器的委托应该是一个视图控制器（包含表的那个）。不要把它放在你的单身！

The delegate of your fetched results controller should be a view controller (the one that contains the table). Do not put it in your singleton!!