ios - 奇怪的问题- "The fetched object at index x has an out of order section name"

我收到以下错误消息:

CoreData: error: (NSFetchedResultsController) The fetched object at index 5 has an out of order section name 'James. Objects must be sorted by section name'
Unresolved search error Error Domain=NSCocoaErrorDomain Code=134060 "The operation couldn’t be completed. (Cocoa error 134060.)" UserInfo=0xaa07530 {reason=The fetched object at index 5 has an out of order section name 'James. Objects must be sorted by section name'}, {
    reason = "The fetched object at index 5 has an out of order section name 'James. Objects must be sorted by section name'";
}

我在SO上经历了无数的答案，这些答案最终最终都指向使用caseInsensitive比较作为答案，但是正如您在下面看到的那样，我的提取请求已设置为执行此操作:

<NSFetchRequest: 0xc082bd0> (entity: InviteeModel; predicate: (eventId == 148 AND typeOf != "InviteeTypeOfServerContact"); sortDescriptors: ((
    "(lastName, ascending, caseInsensitiveCompare:)",
    "(firstName, ascending, caseInsensitiveCompare:)"
)); batch size: 1000; type: NSManagedObjectResultType; )

我似乎已将其范围缩小到以下情况:我有两个姓氏相同的被邀请人(即HENRY JAMES和Henry James)，然后我得到一个错误，上面是说James出故障了。如果我将两个姓氏都更改为James或JAMES，那么它起作用吗？

这是创建获取请求的代码:

NSFetchRequest *fetchRequest = [self buildFetchRequest];

// We have to reset the fetched results controller if the sort changes.
// Because otherwise the scrolling index will be inaccurate.
if (self.fetchedResultsController) {
    if (![self.fetchedResultsController.sectionNameKeyPath isEqualToString:self.sortBy]) {
        self.fetchedResultsController = nil;
    }
}


if (!self.fetchedResultsController) {

    NSManagedObjectContext *context = self.event.managedObjectContext;

    NSString *sectionNameKeyPath = nil;
    if (self.sortBy == DefaultSortBy) {

        sectionNameKeyPath = @"sectionChar";
    }
    else {

        sectionNameKeyPath = self.sortBy;
        if ([self.sortBy isEqualToString:@"rsvpState"] || [self.sortBy isEqualToString:@"checkedIn"]) {
            sectionNameKeyPath = @"lastName";
        }
    }

    NSFetchedResultsController *fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
                                                                                               managedObjectContext:context
                                                                                                 sectionNameKeyPath:sectionNameKeyPath
                                                                                                          cacheName:nil];
    fetchedResultsController.delegate = self;
    self.fetchedResultsController = fetchedResultsController;

这是来自buildFetchRequest的片段，其中添加了sortDescriptors:

        NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:self.sortBy
                                                                       ascending:self.shouldSortAscending
                                                                        selector:@selector(caseInsensitiveCompare:)];

        // Add the default sorts (last, first).
        NSSortDescriptor *lastSort = nil;
        NSSortDescriptor *firstSort = nil;
        if (![self.sortBy isEqualToString:@"lastName"]) {
            lastSort = [NSSortDescriptor sortDescriptorWithKey:@"lastName"
                                                     ascending:YES
                                                      selector:@selector(caseInsensitiveCompare:)];
        }
        if (![self.sortBy isEqualToString:@"firstName"]) {
            firstSort = [NSSortDescriptor sortDescriptorWithKey:@"firstName"
                                                      ascending:YES
                                                       selector:@selector(caseInsensitiveCompare:)];
        }

        NSArray *sorts = nil;

        if (lastSort && firstSort) {
            sorts = [[NSArray alloc] initWithObjects:sortDescriptor, lastSort, firstSort, nil];
        }
        else if (lastSort) {
            sorts = [[NSArray alloc] initWithObjects:sortDescriptor, lastSort, nil];
        }
        else {
            sorts = [[NSArray alloc] initWithObjects:sortDescriptor, firstSort, nil];
        }

        [fetchRequest setSortDescriptors:sorts];

任何想法，这使我发疯。

最佳答案

您正在设置与第一排序描述符键不同的访存结果 Controller 节名称键路径。

   NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc]
           initWithKey:self.sortBy
           ascending:self.shouldSortAscending
           selector:@selector(caseInsensitiveCompare:)];

key 是self.sortBy。

if ([self.sortBy isEqualToString:@"rsvpState"] ||
    [self.sortBy isEqualToString:@"checkedIn"]) {
       sectionNameKeyPath = @"lastName";
}

key 是而不是 self.sortBy。

这应该导致您看到的错误。

关于ios - 奇怪的问题- "The fetched object at index x has an out of order section name"，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/18343312/