-2

当我在运行iOS时，则显示主菜单，以及主菜单类别和产品两部分。当我单击类别时，会发生此错误：

Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayI objectAtIndex:]: index 3 beyond bounds [0 .. 2]

该代码是：

#import "IMScategoriesViewController.h"
#import "IMSAddCategoryViewController.h"
#import "IMSAppDelegate.h"
#import "Category.h"

@interface IMScategoriesViewController ()
@property (strong) NSMutableArray *categories;
@property (nonatomic, retain) NSManagedObjectContext *managedObjectContext;

@end

@implementation IMScategoriesViewController
- (NSManagedObjectContext *)managedObjectContext
{
    NSManagedObjectContext *context = nil;
    id delegate = [[UIApplication sharedApplication] delegate];
    if ([delegate performSelector:@selector(managedObjectContext)]) {
        context = [delegate managedObjectContext];
    }
    return context;
}
- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}
//- (void)viewDidAppear:(BOOL)animated
//{
//    [super viewDidAppear:animated];

   - (void)viewDidLoad
{
    [super viewDidLoad];
    // Fetch the devices from persistent data store
    NSManagedObjectContext *managedObjectContext = [self managedObjectContext];
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"Category"];
    self.categories = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy];

    [self.tableView reloadData];
}
    - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
    {
        // Return the number of sections.
        return 1;
    }

    - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
    {
        // Return the number of rows in the section.
        return self.categories.count;
    }

    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
        static NSString *CellIdentifier = @"Cell";
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

        // Configure the cell...
        NSManagedObject *category = [self.categories objectAtIndex:indexPath.row];
        [cell.textLabel setText:[NSString stringWithFormat:@"%@ %@", [category valueForKey:@"name"], [category valueForKey:@"itemtype"]]];
        //[cell.detailTextLabel setText:[device valueForKey:@"company"]];

      //Category *category = [array objectAtIndex:indexPath.row];

       // cell.textLabel.text =[category  name];
       cell.detailTextLabel.text = [category description];

        return cell;


    }
4

2 回答 2

1

Log类别数组。我看到numberOfRowsInSection基于数组的计数定义为 4，但是类别很可能有一个nil对象。

因此类别数为 4，但尝试访问它时会崩溃。

NSManagedObject *category = [self.categories objectAtIndex:indexPath.row];
于 2013-10-01T17:19:16.180 回答
-1

这显然意味着您正在尝试访问超出其限制的某个数组的索引。找出这个异常涉及哪个数组的最好方法是为所有异常设置一个断点并尝试调试。

于 2013-10-01T17:51:31.283 回答