iOS/Objective-C:删除行后应用程序崩溃

Question

当我尝试从此效率上删除对象/行时，apllication用日志崩溃：

nsinternalInconSistencyException'，原因：'无效更新：无效 第0节中的行数

编辑：

代码中存在更改，现在插入了新对象，并且实际删除了删除的对象，但是只有在崩溃并重新启动后才删除……因此，删除仍然使用相同的日志失败，无效的inttade ...新代码：

    @interface TableViewController ()
@property NSMutableArray *users;
@property NSArray *detailList;
@property (strong) NSMutableArray *locations;

@end
@implementation TableViewController
- (IBAction)delete:(UIBarButtonItem *)sender {
    self.tableView.editing = !self.tableView.editing;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    self.tableView.dataSource = self;
    self.detailList=@[@"Your Favourite Spots",@"Our suggestion"];
}
-(void)viewDidAppear:(BOOL)animated{
    _locations = [[Spot spotType:@"users"]mutableCopy];
    _users=[[Spot spotWithType:@"users"]mutableCopy];
    [self.tableView reloadData];
}

#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 2;
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return [self.detailList objectAtIndex:section];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSArray *places=[self containerWithSection:section];
    return places.count; 
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    NSArray *places=[self containerWithSection:indexPath.section];
    Spot *spot = [places objectAtIndex:indexPath.row];
    [cell.textLabel setText:[NSString stringWithFormat:@"%@", spot.name]];
    return cell;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"detail"]) {
        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        NSArray *places = [self containerWithSection:indexPath.section];
        DetailViewController * destination = segue.destinationViewController;
        destination.spot =  [places objectAtIndex:indexPath.row];

    }
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        NSPersistentContainer *persistenceContainer = [AppDelegate sharedDelegate].persistentContainer;
        NSManagedObjectContext *context = persistenceContainer.viewContext;
        NSMutableArray *places = [self containerWithSection:indexPath.section];
        Spot *spot = [places objectAtIndex:indexPath.row];
        [context deleteObject: spot];
        NSError *error;
        [context save:&error];
        if (!error) {
            NSLog(@"%@", error);
        }
        [places removeObject:spot];

        [self updateItemInSection:indexPath.section];

        [tableView deleteRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationFade];
    }
    [tableView reloadData];
}
#pragma mark - Aux methods
- (void)updateItemInSection:(NSUInteger)section{
    switch (section) {
        case 0:{
            _locations = [[Spot allSpots]mutableCopy];
        }
            break;
        case 1:{
            _users = [[Spot spotType:@"users"]mutableCopy];
        }
            break;    
    }
}

#pragma mark - Aux methods
- (NSMutableArray*)containerWithSection:(NSUInteger)section {
    NSMutableArray *thisContainer;
    switch (section) {
        case 0:
            thisContainer = self.locations;
            break;
        case 1:
            thisContainer = self.users;
            break;   
    }
    return thisContainer;  
}
@end

Answer 1

删除/插入数据对象后，您需要首先更新数据阵列，然后才能要求表recroddata。这就是崩溃的原因，也没有使用新元素进行更新。
如果您考虑这种推理＆amp;尝试一次对您的代码进行必要的更改。
请记住，在任何更改时，插入，删除数据=>首先，更新数据数组=>然后，[table reloadData]

因此，现在为了处理单元格的删除，我们将添加a new 函数updateItemInSection:负责执行表数据更新＆amp;将从tableView:commitEditingStyle:forRowAtIndexPath:调用

它的外观：

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        NSPersistentContainer *persistenceContainer = [AppDelegate sharedDelegate].persistentContainer;
        NSManagedObjectContext *context = persistenceContainer.viewContext;
        NSManagedObject *spot = [_lisbonSpots objectAtIndex:indexPath.section];
        [context deleteObject: spot];
        NSError *error;
        [context save:&error];
        if (!error) {
           NSLog(@"%@", error);        
        }
        [_lisbonSpots removeObject:spot];
        // new function invocation here
        [self updateItemInSection:indexPath.section]; 
        [tableView deleteRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationFade];
    }
}
- (void)updateItemInSection:(NSUInteger)section{
    switch (section) {
        case 0:{
            _bar = [Spot spotType:@"bar"];
        }
            break;
        case 1:{
            _restaurant = [Spot spotType:@"restaurant"];
        }
            break;
        case 2:{
            _club = [Spot spotType:@"club"];
        }
            break;
        case 3:{
            _others = [Spot spotType:@"others"];
        }
            break;
    }
}
- (NSArray*)containerWithSection:(NSUInteger)section {
    NSArray *thisContainer;
    switch (section) {
        case 0:
            thisContainer = self.bar;
            break;
        case 1:
            thisContainer = self.restaurant;
            break;
        case 2:
            thisContainer = self.club;
            break;
        case 3:
            thisContainer = self.others;
            break;
    }
    return thisContainer;
}

Answer 2

问题是名字令人困惑...与编辑的代码，解决方案是：

- (void)updateItemInSection:(NSUInteger)section{
    switch (section) {
        case 0:{
            _locations = [[Spot spotWithType:@"users"]mutableCopy];
        }
            break;
        case 1:{
            _users = [[Spot spotType:@"users"]mutableCopy];
        }
            break;    
    }
}

，但是没有@ystack的帮助