Question

好的伙计们，这就是我的情况。

我正在使用带有Core Data的UITableViewController。该表有大约200个单元格，基本上用作清单。当您点击一个单元格时，该单元格有一个被切换的复选框设置为UITableViewCell.imageView（分配给标签左侧的UIImageView）。

任何时候我使用以下两种方法中的任何一种来更新表，更新大约需要1到2秒......而且据我所知，它似乎正在重新加载每个单元格。如何强制仅更新刚刚被点击的单元格？

[self.tableView reloadData];或

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView beginUpdates];
}

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {

    switch(type) {
        case NSFetchedResultsChangeInsert:
            [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex]
                          withRowAnimation:NO];
            break;

        case NSFetchedResultsChangeDelete:
            [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex]
                          withRowAnimation:NO];
            break;
    }
}

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath {

    UITableView *tableView = self.tableView;

    switch(type) {

        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                             withRowAnimation:NO];
            break;

        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                             withRowAnimation:NO];
            break;

        case NSFetchedResultsChangeUpdate:
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath]
                    atIndexPath:indexPath];
            break;

        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                             withRowAnimation:NO];
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                             withRowAnimation:NO];
            break;
    }
}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView endUpdates];
}

Answer 1

你需要这个：

- (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation

http://developer.apple.com/iphone/library/documentation/uikit/reference/UITableView_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40006943-CH3-SW40

Answer 2

如果您只是更新单元格的文本标签文本 - 此代码就足够了

    UITableViewCell *cell = [_myTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:1]];

    cell.textLabel.text = [NSString stringWithFormat:@"%i", (int)_targetMaxDistanceSlider.value];

在UITableview上仅重新加载一个UITableViewCell

2 个答案: