当我试图在UITableView中拖动单元格最后索引时，得到异常，它只发生在最后一个索引上

Question

在我的应用程序中，我正在执行单元格的重新排序，但我将选定的单元格彼此连接在一起

我有一些单元格，我正在做一些单元格动画，即用户可以选择任何单元格并拖动到我的表中存在的任何单元格，拖动后，这两个单元格被一个用这两个单元格创建的单元格所取代。但我的问题是，当我试图替换最后一个单元格时，它不允许我这样做并且我试图拖动的单元格在底部添加而不替换最后一个单元格并且它只发生在最后一个单元格

Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (50) must be equal to the number of rows contained in that section before the update (51), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).
2013-06-03 15:16:33.636 QuestionPro[6565:1d003] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (50) must be equal to the number of rows contained in that section before the update (51), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'

我的代码

- (void)endedDragGestureWithTranslationPoint:(CGPoint)translation {
[self updateFrameOfDraggedCellForTranlationPoint:translation];
self.draggedCell.layer.shouldRasterize = NO;
[(UITableViewCell *)self.draggedCell setHighlighted:NO animated:YES];
UITableViewCell *oldDraggedCell = [self.draggedCell retain];
NSIndexPath *blankIndexPath = [self.indexPathBelowDraggedCell retain];
CGRect blankCellFrame = oldDraggedCell.frame;
CGPoint blankCellCenter = {
    .x = CGRectGetMidX(blankCellFrame),
    .y = CGRectGetMidY(blankCellFrame)
};
NSIndexPath *rowToMoveTo = [tableView indexPathForRowAtPoint:blankCellCenter];
if ( rowToMoveTo ) {
    CGRect rectForIndexPath = [tableView rectForRowAtIndexPath:rowToMoveTo];
    if (dragGesture.state == UIGestureRecognizerStateFailed ){
        rectForIndexPath = [tableView rectForRowAtIndexPath:self.indexPathBelowDraggedCell];
    }
    NSIndexPath * secIndex = [blankIndexPath copy];
    [UIView animateWithDuration:0.25 delay:0 options:(UIViewAnimationOptionAllowUserInteraction|UIViewAnimationOptionBeginFromCurrentState) animations:^{
        oldDraggedCell.frame = rectForIndexPath;
        [self dragTableViewController:self hideDraggableIndicatorsOfCell:oldDraggedCell];
    } completion:^(BOOL finished) {
        [self dragTableViewController:self removeDraggableIndicatorsFromCell:oldDraggedCell];
        [oldDraggedCell removeFromSuperview];
        [oldDraggedCell release];
    }];
    if (dragGesture.state == UIGestureRecognizerStateEnded && secIndex.row != rowToMoveTo.row ){
        [tableView beginUpdates];
        [self joinTableViewCellsAtFirstRow:rowToMoveTo.row andSecondRow:secIndex.row];
        NSArray * delArray = [[NSArray alloc] initWithObjects:secIndex , nil];
        NSArray * rfrArray = [[NSArray alloc] initWithObjects:secIndex , nil];
        [tableView deleteRowsAtIndexPaths:delArray withRowAnimation:UITableViewRowAnimationNone];
        SALTableCellView * toggledCell = (SALTableCellView *)[tableView cellForRowAtIndexPath:rowToMoveTo];
        if ( toggledCell.selectedImage && activateDelegate ){
            [activateDelegate spotMarkedWithTitle:toggledCell.title andValue:toggledCell.shownValue andColor:[UIColor clearColor]];
        }
        [delArray release];
        [rfrArray release];
        [tableView endUpdates];
        [self recalculateTapSumm];
        [self refreshData];
    }
    else
        hiddenCell.hidden = NO;
    [secIndex release];
    [tableView scrollRectToVisible:rectForIndexPath animated:YES];
}
[blankIndexPath release];
[oldDraggedCell release];

}

Answer 1

好吧，有一个简短的答案和一个长的答案。

简短的回答:你不能做你正在做的，我很惊讶它适用于其他行。

长话短说:你试图做的事情违背了用户"通常"期望发生的事情。ie。如果你把一行从一个地方"移动"到另一个地方，它就会"移动"而不是合并。正如其他人所指出的那样，错误消息说明了这一点。当您删除行时，行数从51变为50。移动行时，数字必须相同。

解决方案:解决方案可能很简单，尽管我自己没有尝试过。试着稍微延迟一下删除和更新这些任务。这样，移动的行就可以完成自己的任务，到那时更新任务就可以删除行并更新数据，以便您可以在目标中显示合并的行。

Answer 2

检查替换单元格前后的行数。

错误提示:替换前的行数不等于替换后的行数