UIPanGestureRecognizer在单元上被调用两次

Question

我正在创建一个UITableView ，您可以从中拖动到另一个UIView并将该单元格转换为自定义UIView 。 我通过向每个单元格添加一个UIPanGestureRecognizer来做到这一点，如果向左滑动，我会创建自定义UIView并为其提供recognizer 。 所有这些工作都很好，只是有时会调用多个识别器。 最终将其拖动到自定义视图及其下的单元格。 我不知道两个视图如何同时识别出锅。 我不能让方法shouldRecognizeSimultaneouslyWithGestureRecognizer返回NO ，因为我必须支持表的scrollView。

这是拖动的代码：

-(void)dragCell:(UIPanGestureRecognizer *)recognizer
{
CGPoint touchLocation = [recognizer locationInView:self.view];

if (recognizer.state == UIGestureRecognizerStateBegan)
{
    gestureWasHandled = NO;
    startPoint = touchLocation;
}
if (recognizer.state == UIGestureRecognizerStateChanged)
{
    float dx = startPoint.x - touchLocation.x;
    float dy = startPoint.y - touchLocation.y;

    BOOL finished = YES;
    BOOL swipeLeft = NO;

    if ((dx > SWIPE_DRAG_MIN) && (ABS(dy) < DRAGLIMIT_MAX))
        swipeLeft = YES;
    else
        finished = NO;

    if (!gestureWasHandled && finished && swipeLeft)
    {
        [symptomsTableView setScrollEnabled:NO];

        UITableViewCell *cell = (UITableViewCell *) recognizer.view;
        NSIndexPath *index = [symptomsTableView indexPathForCell:cell];
        SymptomView *view = [self createSymptomViewAtLocation:touchLocation withSymptom:symptomsInTableView[index.row]];

        [symptomsInTableView removeObjectAtIndex:index.row];
        [cell removeGestureRecognizer:recognizer];
        [view addGestureRecognizer:recognizer];
        gestureWasHandled = YES;
        [symptomsTableView reloadData];
    }
    else if (gestureWasHandled)
    {
        SymptomView *view = (SymptomView *) recognizer.view;
        view.center = touchLocation;
    }
}
if (recognizer.state == UIGestureRecognizerStateEnded)
{
    gestureWasHandled = NO;
    [symptomsTableView setScrollEnabled:YES];

    SymptomView *view = (SymptomView *) recognizer.view;
    [view removeGestureRecognizer:recognizer];
    [symptomsTableView reloadData];
}
}

Answer 1

在viewDidLoad方法中添加self.tableview.canCancelContentTouches = YES 。