ios - 未插入 UITable 的行

Question

我有一个带有展开/折叠部分的表格 View 的应用程序，遵循 Apple 的 Table View Animations & Gestures sample app 中的示例。 .当一个项目被添加到一个关闭的部分时我遇到了问题:之后，该部分不再打开，当我尝试打开然后关闭它时出现异常。

我已经将其追溯到打开/关闭方法中的一些奇怪行为:

-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionOpened:(NSInteger)section {

if (![[sectionHeaderArray objectAtIndex:section] isOpen]) {

    [[sectionHeaderArray objectAtIndex:section] setIsOpen:YES]; 

    NSLog(@"self.tableView: %@", self.tableView);
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
    NSInteger countOfRowsToInsert = [sectionInfo numberOfObjects];

    NSMutableArray *indexPathsToInsert = [[NSMutableArray alloc] init];
    for (NSInteger i = 0; i < countOfRowsToInsert; i++) {
        [indexPathsToInsert addObject:[NSIndexPath indexPathForRow:i inSection:section]];
    }

    // Apply the updates.
    [self.tableView beginUpdates];
    NSLog(@"Count of rows to insert: %d", [indexPathsToInsert count]);
    NSLog(@"Rows before insert: %d", [self.tableView numberOfRowsInSection:section]);
    [self.tableView insertRowsAtIndexPaths:indexPathsToInsert withRowAnimation:UITableViewRowAnimationTop];
    NSLog(@"Rows after insert: %d", [self.tableView numberOfRowsInSection:section]);
    [self.tableView endUpdates];
}

}


-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionClosed:(NSInteger)section {

if ([[sectionHeaderArray objectAtIndex:section] isOpen]) {

    [[sectionHeaderArray objectAtIndex:section] setIsOpen:NO];

    NSInteger countOfRowsToDelete = [self.tableView numberOfRowsInSection:section];

    if (countOfRowsToDelete > 0) {
        NSMutableArray *indexPathsToDelete = [[NSMutableArray alloc] init];
        for (NSInteger i = 0; i < countOfRowsToDelete; i++) {
            [indexPathsToDelete addObject:[NSIndexPath indexPathForRow:i inSection:section]];
        }
        [self.tableView beginUpdates];
        NSLog(@"Count of rows to delete: %d", [indexPathsToDelete count]);
        NSLog(@"Rows before delete: %d", [self.tableView numberOfRowsInSection:section]);
        [self.tableView deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:UITableViewRowAnimationTop];
        NSLog(@"Rows after delete: %d", [self.tableView numberOfRowsInSection:section]);

    }

    [self.tableView endUpdates];
}
}

日志消息显示，在打开(插入行)时，插入了 >0 行，但该部分的行数仍为 0:

2012-03-31 13:36:17.454 QuickList7[5523:fb03] Count of rows to insert: 3
2012-03-31 13:36:17.454 QuickList7[5523:fb03] Rows before insert: 0
2012-03-31 13:36:17.454 QuickList7[5523:fb03] Rows after insert: 0

这在表和数据源之间设置了不一致的状态，然后当我尝试“折叠”该部分时，出现以下异常:

2012-03-31 13:48:35.783 QuickList7[5523:fb03] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid table view update.  The application has requested an update to the table view that is inconsistent with the state provided by the data source.'

我怎样才能插入 3 行，最后仍然是 0 行？

谢谢，

萨沙

Answer 1

我找到问题了!它实际上在 fetchedResultsController 的更改处理程序中。它正在响应对关闭部分的更改，这使表处于错误状态，并且与数据源不同步。所以我为每个更新添加了一个检查，以仅在包含部分打开时插入/删除/更新行。

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
   atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
  newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tv = self.tView;
switch(type) {
    case NSFetchedResultsChangeInsert:
        if ([[sectionHeaderArray objectAtIndex:newIndexPath.section] isOpen]) {
            [tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
        }
        break;

    case NSFetchedResultsChangeDelete:
        if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
            [tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        }
        break;

    case NSFetchedResultsChangeUpdate:
        if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
            [self configureCell:[tv cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
        }
        break;

    case NSFetchedResultsChangeMove:
        if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
            [tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        }
        if ([[sectionHeaderArray objectAtIndex:newIndexPath.section] isOpen]) {
            [tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
        }
        break;
}

}