ios - UIGestureRecognizer 和 UITableViewCell 问题

Question

我将 UISwipeGestureRecognizer 附加到 cellForRowAtIndexPath: 方法中的 UITableViewCell，如下所示:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

        UISwipeGestureRecognizer *gesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(didSwipe:)];
        gesture.direction = UISwipeGestureRecognizerDirectionRight;
        [cell.contentView addGestureRecognizer:gesture];
        [gesture release];
    }
    return cell;
}

但是，didSwipe 方法总是在成功滑动时被调用两次。我最初认为这是因为手势开始和结束，但如果我注销 gestureRecognizer 本身，它们都处于“已结束”状态:

-(void)didSwipe:(UIGestureRecognizer *)gestureRecognizer {

    NSLog(@"did swipe called %@", gestureRecognizer);
}

控制台:

2011-01-05 12:57:43.478 App[20752:207] did swipe called <UISwipeGestureRecognizer: 0x5982fa0; state = Ended; view = <UITableViewCellContentView 0x5982c30>; target= <(action=didSwipe:, target=<RootViewController 0x5e3e080>)>; direction = right>
2011-01-05 12:57:43.480 App[20752:207] did swipe called <UISwipeGestureRecognizer: 0x5982fa0; state = Ended; view = <UITableViewCellContentView 0x5982c30>; target= <(action=didSwipe:, target=<RootViewController 0x5e3e080>)>; direction = right>

我真的不知道为什么。我显然尝试检查 Ended 状态，但这无济于事，因为无论如何它们都是“Ended”...有什么想法吗？

Answer 1

您可以将手势识别器添加到 viewDidLoad 中的 tableview，而不是直接将手势识别器添加到单元格。

在 didSwipe-方法中，您可以确定受影响的 IndexPath 和单元格，如下所示:

-(void)didSwipe:(UIGestureRecognizer *)gestureRecognizer {

  if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
        CGPoint swipeLocation = [gestureRecognizer locationInView:self.tableView];
        NSIndexPath *swipedIndexPath = [self.tableView indexPathForRowAtPoint:swipeLocation];
        UITableViewCell* swipedCell = [self.tableView cellForRowAtIndexPath:swipedIndexPath];
        // ...
  }
}