我有一个应用,它在视图的下半部分有一个文本框。 这意味着当我在文本框中输入时,键盘会覆盖文本框。

我如何在打字时向上移动视图,这样我就可以看到我键入的内容,然后在键盘消失时将它移回原来的位置?

我到处都看了,但所有的解似乎都在Obj-C中,我还不能完全转换。

任何帮助都将不胜感激。


当前回答

验证的答案没有考虑到文本字段的位置,并有一些错误(双位移,永远不会回到主位置,位移即使文本字段是在视图的顶部…)

这个想法是:

获取焦点TextField的Y的绝对位置 来获取键盘高度 来获取屏幕高度 然后计算键盘位置和文本框之间的距离(如果< 0 ->向上移动视图) 使用UIView。而不是UIView.frame.origin.y -= ..,因为用UIView更容易回到原来的位置。变换= .identity

然后,我们将能够移动视图,只有在必要和特定的位移,以便有聚焦texField刚刚超过键盘

代码如下:

斯威夫特4

class ViewController: UIViewController, UITextFieldDelegate {

var textFieldRealYPosition: CGFloat = 0.0

override func viewDidLoad() {
    super.viewDidLoad()

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

  // Delegate all textfields

}


@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        let distanceBetweenTextfielAndKeyboard = self.view.frame.height - textFieldRealYPosition - keyboardSize.height
        if distanceBetweenTextfielAndKeyboard < 0 {
            UIView.animate(withDuration: 0.4) {
                self.view.transform = CGAffineTransform(translationX: 0.0, y: distanceBetweenTextfielAndKeyboard)
            }
        }
    }
}


@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.4) {
        self.view.transform = .identity
    }
}


func textFieldDidBeginEditing(_ textField: UITextField) {
  textFieldRealYPosition = textField.frame.origin.y + textField.frame.height
  //take in account all superviews from textfield and potential contentOffset if you are using tableview to calculate the real position
}

}

其他回答

我需要在swift 4中移动一个UIView,当键盘打开和关闭。所有的答案都帮不了我。因为打开表情包时键盘高度会发生变化。所以我的代码是:

@objc func keyboardWillShow(sender: NSNotification) {

    if let keyboardFrame: NSValue = sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {

        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height

        if(self.oldHeight == keyboardHeight){
            self.sendingView.frame.origin.y -= keyboardHeight
            self.oldHeight = keyboardHeight
        }
        else{
            self.sendingView.frame.origin.y += self.oldHeight
            self.sendingView.frame.origin.y -= keyboardHeight
            self.oldHeight = keyboardHeight
        }
    }
}

@objc func keyboardWillHide(sender: NSNotification) {

    if let keyboardFrame: NSValue = sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {

        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height

        self.sendingView.frame.origin.y += keyboardHeight

    }
}

和在viewDidLoad():

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);

自我。oldHeight = CGFloat()并定义为类顶部的字段。

斯威夫特4:

我有一个问题与最接受的答案,其中隐藏键盘并没有返回视图一直到页面的底部(只是部分)。这对我来说很有效(+为Swift 4更新)。

override func viewDidLoad() {
    super.viewDidLoad()
    self.hideKeyboardWhenTappedAround()
    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)
}

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0{
            self.view.frame.origin.y -= keyboardSize.height
        }
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y != 0{
            self.view.frame.origin.y = 0
        }
    }
}
 override func viewWillAppear(animated: Bool)
 {
 super.viewWillAppear(animated)

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

 }

 // MARK: - keyboard
 func keyboardWillShow(notification: NSNotification) 
{

if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: keyboardSize.height, right:contentInsets.right)
                    // ...
                } else {
                    // no UIKeyboardFrameBeginUserInfoKey entry in userInfo
                }
            } else {
                // no userInfo dictionary in notification
            }
        }

func keyboardWillHide(notification: NSNotification) 
{
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: 0, right:contentInsets.right)
 }

所以其他答案似乎都不正确。

iOS上的良好行为键盘应该:

键盘改变大小时自动调整大小(YES IT CAN) 动画的速度与键盘相同 使用与键盘相同的曲线进行动画 如果相关,尊重安全区域。 也适用于iPad/Undocked模式

我的代码使用一个声明为@IBOutlet的NSLayoutConstraint

@IBOutlet private var bottomLayoutConstraint: NSLayoutConstraint!

你也可以使用变换,视图偏移量,....我觉得有了约束就容易多了。它通过在底部设置一个约束来工作,如果你的常量不是0/不是底部,你可能需要修改代码。

代码如下:

// In ViewDidLoad
    NotificationCenter.default.addObserver(self, selector: #selector(?MyViewController.keyboardDidChange), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)


@objc func keyboardDidChange(notification: Notification) {
    let userInfo = notification.userInfo! as [AnyHashable: Any]
    let endFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
    let animationDuration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! NSNumber
    let animationCurve = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as! NSNumber
    bottomLayoutConstraint.constant = view.frame.height - endFrame.origin.y - view.safeAreaInsets.bottom // If your constraint is not defined as a safeArea constraint you might want to skip the last part.
    // Prevents iPad undocked keyboard.
    guard endFrame.height != 0, view.frame.height == endFrame.height + endFrame.origin.y else {
        bottomLayoutConstraint.constant = 0
        return
    }
    UIView.setAnimationCurve(UIView.AnimationCurve(rawValue: animationCurve.intValue)!)
    UIView.animate(withDuration: animationDuration.doubleValue) {
        self.view.layoutIfNeeded()
        // Do additional tasks such as scrolling in a UICollectionView
    }
}

将这个添加到你的视图控制器中。效果非常好。只是调整数值。

override func viewDidLoad() {
    super.viewDidLoad()        
    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);
}

@objc func keyboardWillShow(sender: NSNotification) {
    self.view.frame.origin.y -= 150
}
@objc func keyboardWillHide(sender: NSNotification) {
    self.view.frame.origin.y += 150
}