Question

我的申请表中有登录和注册表格。当用户点击任何textField时，我会计算键盘和textField的高度差，并在需要时滚动我的视图。

为此，我在loginVC中添加了两个观察者：

NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)

func keyboardWillShow(notification: NSNotification) {
    println("keyb show")
    keyboardIsShown = true
    keyboardHeight = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().height
    calculateAnimationValue()
}

func keyboardWillHide(notification: NSNotification) {
    println("keyb hide")
    keyboardIsShown = false
    animateViewMoving(false, moveValue: animationValue)
    animationValue = 0
}

func textFieldDidBeginEditing(textField: UITextField) {
    pressedTextField = textField
    textField.becomeFirstResponder()
    if keyboardIsShown {
        calculateAnimationValue()
    }
}

func calculateAnimationValue() {
    if keyboardHeight != nil {
        var windowHeight = self.view.frame.height
        var textFieldY = pressedTextField.frame.origin.y
        var windowWithoutKeyboard = windowHeight - keyboardHeight - 44
        if textFieldY > windowWithoutKeyboard {
            if animationValue < (textFieldY - windowWithoutKeyboard) {
                animationValue = animationValue + textFieldY - windowWithoutKeyboard
                animateViewMoving(true, moveValue: animationValue)
            }
        }
    }
    println(animationValue)
}

func animateViewMoving (up: Bool, moveValue: CGFloat){
    var movementDuration: NSTimeInterval = 0.3
    var movement:CGFloat = (up ? -moveValue : moveValue)
    UIView.beginAnimations("animateView", context: nil)
    UIView.setAnimationBeginsFromCurrentState(true)
    UIView.setAnimationDuration(movementDuration)
    self.view.frame = CGRectOffset(self.view.frame, 0, movement)
    UIView.commitAnimations()
}

但是我想在registrationVC中做同样的事情。

如何在另一个VC中使用keyboardWillShow，keyboardWillHide？

我尝试添加相同的观察者但是应用程序在loginVC中不在registrationVC中触发这些方法。

有人可以帮助我吗？

更新：------------------------

class LogInViewController: UIViewController, UITextFieldDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    func keyboardWillShow(notification: NSNotification) {
        println("keyb show")
    }

    func keyboardWillHide(notification: NSNotification) {
        println("keyb hide")
    }

}

class RegistrationViewController: UIViewController, UITextFieldDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    func keyboardWillShow(notification: NSNotification) {
        println("keyb show2")
    }

    func keyboardWillHide(notification: NSNotification) {
        println("keyb hide2")
    }

    deinit {
        println("deinit")
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }
}

如果我在loginVC上触摸textField并且segue到registerVC它运行良好并打印“keyb show2”。

但是如果没有在loginVC上触摸textField并且segue到registerVC并触摸textField则会打印“keyb show”。这是从以前的控制器调用的。我做错了什么？

如何在不同的ViewControllers中使用observer选择器函数

0 个答案: