如长按手势：

cell长按事件添加（tableView和collectionView相同）
1，添加长按手势

- (void)addLongPressGesture {
    UILongPressGestureRecognizer *longPressGR = [[UILongPressGestureRecognizer alloc] initWithTarget:self
                                                                                              action:@selector(longPressToDo:)];
    longPressGR.minimumPressDuration = kLongPressDuration;
    [self.collectionView addGestureRecognizer:longPressGR];
}

2，手势处理

- (void)longPressToDo:(UILongPressGestureRecognizer *)gesture {
    if (gesture.state == UIGestureRecognizerStateBegan) {
        CGPoint point = [gesture locationInView:self.collectionView];
        NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:point];
        // ...code...
    }
}