在UIScrollView中关闭UITextField小数键盘

我正在寻找解决问题的方法，但是所有发现的建议都行不通。

我从基于两个TextField带小数点的工作解决方案开始。当我在没有回车键的情况下，轻按任意位置以关闭键盘，我成功使用了：

view.endEditing(true)

当我决定添加UIScrollView以便向上移动UITextField屏幕底部时，我的问题开始了。

view.endEditing（true）不起作用，因为滚动视图覆盖了视图。我添加了一个TapGestureRecognizer，除了键盘关闭以外，其他所有功能都起作用。

在TapGestureReconizer函数下，如果我在应用程序崩溃时使用resignFirstResponder，则会出错：activeTextFiledAppDelegate

线程1：信号SIGABRT。

class ViewController: UIViewController, UITextFieldDelegate {

    var activeField: UITextField?

    @IBOutlet weak var textFieldTop: UITextField!
    @IBOutlet weak var textFieldBottom: UITextField!
    @IBOutlet weak var scrollView: UIScrollView!

    func textFieldDidBeginEditing(textField: UITextField) {
        activeField = textField
    }

    func textFieldDidEndEditing(textField: UITextField) {
        activeField = nil
    } 

    func registerForKeyboardNotifications() {
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden", name: UIKeyboardWillHideNotification, object: nil)
    }

    func deregisterFromKeyBoardNotification() {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }

    func keyboardWasShown(notification: NSNotification) {
        self.scrollView.scrollEnabled = true
        let info : NSDictionary = notification.userInfo!
        let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().size
        let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height + 20, 0.0)

        self.scrollView.contentInset = contentInsets
        self.scrollView.scrollIndicatorInsets = contentInsets

        var aRect : CGRect = self.view.frame
        aRect.size.height -= keyboardSize!.height
        if let _ = activeField
        {
            if (!CGRectContainsPoint(aRect, activeField!.frame.origin))
            {
                self.scrollView.scrollRectToVisible(activeField!.frame, animated: true)
            }
        }
        self.scrollView.scrollEnabled = false
    }

    func keyboardWillBeHidden(notification: NSNotification)
    {
        let info : NSDictionary = notification.userInfo!
        let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().size
        let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, -keyboardSize!.height, 0.0)
        self.scrollView.contentInset = contentInsets
        self.scrollView.scrollIndicatorInsets = contentInsets
        self.scrollView.scrollEnabled = false
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        registerForKeyboardNotifications()
        self.textFieldBottom.delegate = self
        self.textFieldTop.delegate = self

        scrollView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "closeKeyboard"))

    }

    func closeKeyboard() {
        activeField?.resignFirstResponder()

    }
}

我尝试了不同的解决方案，但没有一个在工作。