swift 3 如何让UIAlertView出现在手指离开之前?

How to make a UIAlertView appears before the finger lift off in swift 3?

我有一个 UITableView,我想制作一个 UIAlertView 出现在 UILongPressGestureRecognizer 上。

它现在运行良好,我必须将手指从屏幕上移开才能看到它出现。

有没有办法让它在0.5秒后(例如)出现,即使手指还在屏幕上? 用属性的UILongPressGestureRecognizer?

编辑:

class Settings: UIViewController , UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
    super.viewDidLoad()

    let longPress = UILongPressGestureRecognizer(target: self, action: #selector(Settings.deleteItem))
    self.tableView.addGestureRecognizer(longPress)
}

func deleteItem(longPress:UIGestureRecognizer) {
    if longPress.state == UIGestureRecognizerState.ended {
        let pressedLocation = longPress.location(in: self.tableView)
        if let pressedIndexPath = tableView.indexPathForRow(at: pressedLocation) { //Give the row where it's touched

            RowSelected = (actionList?[pressedIndexPath[1]])!
            print(RowSelected)
            longtouched = pressedIndexPath[1]
            let alert = UIAlertController(title: "What do you want to do?", message: "Select the action you want to do.", preferredStyle: UIAlertControllerStyle.alert)

            let Cancel = UIAlertAction(title: "Cancel", style: .default) { actio in
                print("Canceled")
            }


            let Delete = UIAlertAction(title: "Delete", style: .default) { actio in
                //DOING MY STUFF

            }

            let Modify = UIAlertAction(title: "Modify", style: .default) { actio in
                UserDefaults.standard.set(self.longtouched, forKey: "modify")
                self.performSegue(withIdentifier: "ToModify", sender: self)
            }
            alert.addAction(Modify)
            alert.addAction(Delete)
            alert.addAction(Cancel)
            self.present(alert, animated: true, completion: nil)
        }
    }
}

其实我已经亲眼看到了这个问题。

如果有人遇到同样的问题,只需将 if longPress.state == UIGestureRecognizerState.ended 更改为 if longPress.state == UIGestureRecognizerState.began 它会成功的。