Swift 显示隐藏顶部消息的键盘

当键盘出现在视图控制器上时，隐藏页面顶部消息

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将文本字段与键盘一起使用有两种类型

第一类

您必须声明textfield并遵循通知观察者，就像我在应用程序中所做的那样。 这样申报

var textField: UITextField?

使用此功能

func registerForKeyboardNotifications()
{
    //Adding notifies on keyboard appearing
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
}


func deregisterFromKeyboardNotifications()
{
    //Removing notifies on keyboard appearing
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}

func keyboardWasShown(notification: NSNotification)
{

    self.scrollView.scrollEnabled = true
    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 = textField
    {
        if (!CGRectContainsPoint(aRect, textField!.frame.origin))
        {
            self.scrollView.scrollRectToVisible(textField!.frame, animated: true)
        }
    }


}


func keyboardWillBeHidden(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
    self.view.endEditing(true)
    self.scrollView.scrollEnabled = false

}

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

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

您必须在VC的Viewdidload函数中声明此代码

self.textField.delegate = self

第二类

在编写texFieldDidBeginEditing函数或其他方法时，如果您在使用iboutlet时没有声明textfield，那么在连接到textfields时将声明两件事

Touchupinside 
TouchDidBeginEditing

最后，你必须给出函数。在故事板中连接代理 编写此代码

 func registerForKeyboardNotifications()
    {
        //Adding notifies on keyboard appearing
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
    }


    func deregisterFromKeyboardNotifications()
    {
        //Removing notifies on keyboard appearing
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }

    func keyboardWasShown(notification: NSNotification)
    {

        self.scrollView.scrollEnabled = true
        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 = textField
        {
            if (!CGRectContainsPoint(aRect, textField!.frame.origin))
            {
                self.scrollView.scrollRectToVisible(textField!.frame, animated: true)
            }
        }


    }


    func keyboardWillBeHidden(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
        self.view.endEditing(true)
        self.scrollView.scrollEnabled = false

    }

可能重复的