出现键盘时向上移动视图

Question

问题：

我有一个 ViewController，它有一个包含 UIScrollView 的子类。

scrollView 中有 3 个 UITextField。其中 2 个带有 numberPad 键盘，1 个带有 UIPickerView 键盘。

问题是当键盘出现时，它隐藏了 UITextFields。所以我要做的是在显示键盘时将 UIViewController 的视图向上移动。

我已经尝试过的：

我在 SO 上搜索了这个问题，找到了一些答案，基于它们我写了这段代码：

override func viewDidLoad() {
    super.viewDidLoad()

    //Keyboard notifications
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

//MARK: - keyboards

@objc fileprivate func keyboardWillShow(notification: Notification) {
    self.changeViewOriginBasedOnKeyboardPosition(notification: notification)
}

@objc fileprivate func keyboardWillHide(notification: Notification) {
    self.changeViewOriginBasedOnKeyboardPosition(notification: notification)
}

fileprivate func changeViewOriginBasedOnKeyboardPosition(notification: Notification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardAnimationDuration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! TimeInterval
        UIView.animate(withDuration: keyboardAnimationDuration != 0 ? keyboardAnimationDuration : 0.2, animations: {
            if self.controllerContentView.frame.origin.y == 0  {
                self.controllerContentView.frame.origin.y = -keyboardSize.height
            } else {
                self.controllerContentView.frame.origin.y = 0
            }
        })
    }
}

fileprivate func dismissKeyboard() {
    self.view.endEditing(true)
}

//Touch handling

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    self.dismissKeyboard()
}

我试过的问题：

有时效果很好，但有时视图 "jumps" 备份/"jumps" 下降，我不明白为什么。

有没有人发现我的代码存在任何可能导致此错误的问题？

谢谢！

Answer 1

您需要根据键盘隐藏设置高度。有四个键盘观察器可用。

1) UIKeyboardWillShow
2) UIKeyboardDidShow
3) UIKeyboardWillHide
4) UIKeyboardDidHide

您需要注册键盘观察者：

NotificationCenter.default.addObserver(self, selector: #selector(keyboardShowNotification), name:NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardHideNotification), name:NSNotification.Name.UIKeyboardWillHide, object: nil)

这里是方法观察者方法：

func keyboardShowNotification(notification:NSNotification){

    var userInfo = notification.userInfo!
    var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
    keyboardFrame = self.view.convert(keyboardFrame, from: nil)

    var contentInset:UIEdgeInsets = YOUR_SCROLLVIEW_OBJ.contentInset
    contentInset.bottom = keyboardFrame.size.height
    YOUR_SCROLLVIEW_OBJ.contentInset = contentInset
}

func keyboardHideNotification(notification:NSNotification){
    let contentInset:UIEdgeInsets = UIEdgeInsets.zero
    YOUR_SCROLLVIEW_OBJ = contentInset
}

另一个处理键盘的最佳键是IQKeyboardManager。您只需将它们添加到您的应用程序中，它就会处理所有事情。

Answer 2

我为此使用了一个名为 IQKeyboardManager 的 CocoaPod。

https://github.com/hackiftekhar/IQKeyboardManager

设置起来非常简单，并且可以在全球范围内使用。

出现键盘时向上移动视图

Move view up when keyboard is presented

iphone

cocoa-touch

uitextfield

ios

swift