如何处理此案：UITouch的位置不在UITableView中

Question

我正在尝试使用longPressGesture移动tableView单元格。
当发件人位置在tableView中时，它工作良好。
问题是当我释放拖出tableView的拖动时，快照被冻结。 stat.default不起作用。
我需要你的帮助。谢谢！

var originIndexPath: IndexPath?
var initialSnapshot: UIView?

@IBAction func LongPress(_ sender: UILongPressGestureRecognizer) {

    let state = sender.state
    let location = sender.location(in: tableView)
    guard let indexPath = self.tableView.indexPathForRow(at: location) else { return }
    switch state {
        case .began:
                originIndexPath = indexPath
                guard let cell = self.tableView.cellForRow(at: indexPath) else { return }
                initialSnapshot = cellSnapshot(inputView: cell)
                guard let snapshot = initialSnapshot else { return }
                var center = cell.center
                snapshot.center = center
                snapshot.alpha = 0.0
                self.tableView.addSubview(snapshot)
                UIView.animate(withDuration: 0.25, animations: {
                    center.y = location.y
                    snapshot.center = center
                    snapshot.transform = CGAffineTransform(scaleX: 1.05, y: 1.05)
                    snapshot.alpha = 0.98
                    cell.alpha = 0.0
                }, completion:{(finished) in cell.isHidden = true })

        case .changed:
            guard let snapshot = initialSnapshot else { return }
            var center = snapshot.center
            center.y = location.y

            snapshot.center = center
            guard let sourceIndexPath = originIndexPath else { return }

            if indexPath.section != sourceIndexPath.section {
                if indexPath.row + 1 == tableView.numberOfRows(inSection: indexPath.section){
                    originIndexPath = IndexPath(row: indexPath.row + 1, section: indexPath.section)
                    }else{ originIndexPath = indexPath }
                let cataitem = fetchedResultsController.object(at: sourceIndexPath )
                cataitem.category = NSNumber(value: indexPath.section).boolValue
                    saveContext()
            }
            else if indexPath.row != sourceIndexPath.row {
                tableView.moveRow(at: sourceIndexPath, to: indexPath)
                originIndexPath = indexPath
            }

        default:
            guard let cell = self.tableView.cellForRow(at: originIndexPath!) else {return}
            guard let snapshot = initialSnapshot else {return}
            cell.isHidden = false
            cell.alpha = 0.0
            UIView.animate(withDuration: 0.25, animations: {
                snapshot.center = cell.center
                snapshot.transform = CGAffineTransform.identity
                snapshot.alpha = 0
                cell.alpha = 1
            }, completion: { (finished) -> Void in
                if finished {
                    self.originIndexPath = nil
                    snapshot.removeFromSuperview()
                    self.initialSnapshot = nil
                }})
    }

}