单击UITextView时无法移动键盘

Question

当键盘弹出时，我尝试让UITextField和UITextView向上移动。 但是，我发现它只适用于UITextField，但不适用于UITextView。 我错过了什么吗？

textFields和textViews都是委派的。

这是我的代码：

var activeField: UITextField?
var activeView: UITextView?

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


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

func keyboardWasShown(notification: NSNotification)
{
    var info : NSDictionary = notification.userInfo!
    var keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().size
    var contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height, 0.0)

    self.scrollview.contentInset = contentInsets
    self.scrollview.scrollIndicatorInsets = contentInsets

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

    if let activeViewPresent = activeView
    {
        if (!CGRectContainsPoint(aRect, activeView!.frame.origin))
        {
            self.scrollview.scrollRectToVisible(activeView!.frame, animated: true)
        }
    }
}


func keyboardWillBeHidden(notification: NSNotification)
{
    var info : NSDictionary = notification.userInfo!
    var keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().size
    var contentInsets : UIEdgeInsets = UIEdgeInsetsZero
    self.scrollview.contentInset = contentInsets
    self.scrollview.scrollIndicatorInsets = contentInsets
    self.view.endEditing(true)
}

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

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

func textViewDidBeginEditing(textView: UITextView) {
    activeView = textView
    registerForKeyboardNotifications()
}

func textViewDidEndEditing(textView: UITextView) {
    deregisterFromKeyboardNotifications()
    activeView = nil
}