3

我知道错误发生在这一行,因为应用程序在注释掉这一行的情况下工作得很好:

controller.managedObjectContext = self.managedObjectContext;

错误是:

由于未捕获的异常“NSInvalidArgumentException”而终止应用程序,原因:“-[UITableViewController setManagedObjectContext:]: unrecognized selector sent to instance 0x7490da0”

fibroMappAppDelegate.h

//
//  fibroMappAppDelegate.h
//  fibromapp
//
//  Created by jamie mcallister on 09/08/2013.
//  Copyright (c) 2013 Jamie McAllister. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface fibroMappAppDelegate : 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;

- (void)saveContext;
- (NSURL *)applicationDocumentsDirectory;

@end

和 fibroMappAppDelegate.m

//
//  fibroMappAppDelegate.m
//  fibromapp
//
//  Created by jamie mcallister on 09/08/2013.
//  Copyright (c) 2013 Jamie McAllister. All rights reserved.
//

#import "fibroMappAppDelegate.h"

#import "fibroMappMasterViewController.h"

@implementation fibroMappAppDelegate

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

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
   fibroMappMasterViewController *controller = (fibroMappMasterViewController *)navigationController.topViewController;
    controller.managedObjectContext = self.managedObjectContext;
    return YES;
}

- (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:@"fibromapp" 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 (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }

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

    NSError *error = nil;
    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![_persistentStoreCoordinator 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. 

         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:
     @{NSMigratePersistentStoresAutomaticallyOption:@YES, NSInferMappingModelAutomaticallyOption:@YES}

     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

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

@end
4

3 回答 3

3

这意味着当你这样做时:

controller.managedObjectContext = self.managedObjectContext;

controller没有属性,managedObjectContext所以不可能给它分配任何东西。您没有controller发布UITableViewController. 如果您想以正确的方式解决此问题,您需要提供controller一个managedObjectContext属性,以便您可以进行此分配。

于 2013-08-23T16:40:37.527 回答
2

您所要做的就是删除此行:

controller.managedObjectContext = self.managedObjectContext;

并且每当您需要在视图中使用托管对象上下文时:

[(fibroMappAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
于 2013-08-23T16:26:09.077 回答
2

该错误表明您正在使用非子类 UITableViewController 并认为您正在使用具有名为的属性的子类managedObjectContext。检查你的故事板、xib 或代码,看看发生了什么。

由于您正在尝试使用依赖注入(顺便说一句,这是一件非常好的事情),所以我建议检查您在哪里创建controller并更改它,以便它使用UITableViewController具有正确属性的子类。

于 2013-08-23T16:40:53.073 回答