使用核心数据时出现不一致错误

Posted 2023-03-05

【中文标题】使用核心数据时出现不一致错误

【英文标题】：Getting Inconsistantcy Error When Using Core Data

【发布时间】：2011-04-07 02:54:40

【问题描述】：

当我点击下面发布的 viewController 时，我收到一条错误消息：

* 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“-[Routine isEqualToString:]：无法识别的选择器发送到实例 0x9c05320”

谁能帮我完成这项工作？

这是我的代码：

@implementation RoutineTableViewController

@synthesize tableView;
@synthesize eventsArray;
@synthesize entered;
@synthesize managedObjectContext;

#pragma mark - View lifecycle

- (void)viewDidLoad

    if (managedObjectContext == nil) 
     
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
    

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Routine" inManagedObjectContext:managedObjectContext];
    [request setEntity:entity];

    NSError *error = nil;
    NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
    if (mutableFetchResults == nil) 
        // Handle the error.
    
    [self setEventsArray:mutableFetchResults];
    [mutableFetchResults release];
    [request release];

    UIBarButtonItem * addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showPrompt)];
    [self.navigationItem setLeftBarButtonItem:addButton];
    [addButton release];

    UIBarButtonItem *editButton = [[UIBarButtonItem alloc]initWithTitle:@"Edit" style:UIBarButtonItemStyleBordered target:self action:@selector(toggleEdit)];
    self.navigationItem.rightBarButtonItem = editButton;
    [editButton release];

    [super viewDidLoad];


- (void)viewDidUnload

    self.eventsArray = nil;
    [super viewDidUnload];


-(void)toggleEdit

    [self.tableView setEditing: !self.tableView.editing animated:YES];

    if (self.tableView.editing)
        [self.navigationItem.rightBarButtonItem setTitle:@"Done"];
    else
        [self.navigationItem.rightBarButtonItem setTitle:@"Edit"];


- (void)dealloc

    [managedObjectContext release];
    [eventsArray release];
    [super dealloc];


- (void)didReceiveMemoryWarning

    [super didReceiveMemoryWarning];


#pragma mark -
#pragma mark Add an event

-(void)addEvent
    
    Routine *routine = (Routine *)[NSEntityDescription insertNewObjectForEntityForName:@"Routine" inManagedObjectContext:managedObjectContext];

    routine.name=entered;

    NSError *error = nil;
    if (![managedObjectContext save:&error]) 
        // Handle the error.
    
    NSLog(@"%@", error);

    [eventsArray insertObject:routine atIndex:0];

    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];

    [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

    [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];


-(void)showPrompt

    AlertPrompt *prompt = [AlertPrompt alloc];
    prompt = [prompt initWithTitle:@"Add Workout Day" message:@"\n \n Please enter title for workout day" delegate:self cancelButtonTitle:@"Cancel" okButtonTitle:@"Add"];
    [prompt show];
    [prompt release];


- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex

    if (buttonIndex != [alertView cancelButtonIndex])
    
        entered = [(AlertPrompt *)alertView enteredText];
        if(eventsArray && entered)
        
            [eventsArray addObject:entered];
            [tableView reloadData];
            [self addEvent];
        
    


#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

    return 1;


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

    return [eventsArray count];


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

    static NSString *CellIdentifier = @"Cell";

    // Dequeue or create a new cell.

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil)
    
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    

    Routine *routine = (Routine *)[eventsArray objectAtIndex:indexPath.row];
    cell.textLabel.text = [self.eventsArray objectAtIndex:indexPath.row];

    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    return cell;



// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath

    // Return NO if you do not want the specified item to be editable.
    return YES;


-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
 

     if (editingStyle == UITableViewCellEditingStyleDelete) 

         // Delete the managed object at the given index path.
         NSManagedObject *eventToDelete = [eventsArray objectAtIndex:indexPath.row];
         [managedObjectContext deleteObject:eventToDelete];

         // Update the array and table view.
         [eventsArray removeObjectAtIndex:indexPath.row];
         [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];

         // Commit the change.
         NSError *error = nil;
         if (![managedObjectContext save:&error]) 
             // Handle the error.
         
     
 

【参考方案1】：

您可能正在使用 Routine 对象，而您应该使用 NSString。如果没有更多关于异常在巨大代码转储中的确切位置的信息，我只能猜测，但这在tableView:cellForRowAtIndexPath: 中看起来特别可疑：

Routine *routine = (Routine *)[eventsArray objectAtIndex:indexPath.row];
cell.textLabel.text = [self.eventsArray objectAtIndex:indexPath.row];

如果数组中的值确实是Routine，那么将该对象分配给标签的text 属性很可能是错误的。

【讨论】：

是的，这就是错误的来源。我怎样才能解决这个问题？它应该是来自名为 Routine 的实体的 name 属性中的文本。

然后将[routine name] 分配给text 属性。但请注意，据我所知，您已将 Routine 对象和 NSStrings 都插入到 eventsArray 中。您可能应该重组您的代码以不这样做，或者如果绝对必要，您可以使用 isKindOfClass: 来了解任何特定对象是例程（意味着您需要调用 [routine name] 来获取字符串）还是 NSString。

谢谢阿诺米。好的，所以我没有理由在 eventsArray 中有 Routine 对象和 NSStrings。我相信 eventsArray 应该只包含将在表格视图中显示的获取数据，对吗？我怎样才能重组我的代码来做到这一点？

@Faisal：你为什么这么认为？

你说我在 eventsArray 中插入了 Routine 对象和 NSStrings。我认为它应该只适用于 nsstrings 对吧？我不确定如何准确解决这个问题。这是我第一次将 Core Data 添加到应用程序中