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

我做了一个椰子荚来简化问题:

https://github.com/xtrinch/KeyboardLayoutHelper

如何使用:

做一个自动布局底部约束,在模块KeyboardLayoutHelper中给它一个KeyboardLayoutConstraint类,pod将做必要的工作来增加它,以适应出现和消失的键盘。关于如何使用它(我做了两个:一个scrollView内的textFields,和垂直居中的textFields与两个基本视图-登录和注册)的例子项目。

底部布局约束可以是容器视图,textField本身,任何你能想到的。

其他回答

我已经阅读了答案,并通过以下代码行解决了我的问题:

class ViewController: UIViewController, UITextFieldDelegate {

  @IBOutlet weak var titleField: UITextField!
  @IBOutlet weak var priceField: UITextField!
  @IBOutlet weak var detailsField: UTtextField!

  override func viewDidLoad() {
   super.viewDidLoad()
// Do not to forget to set the delegate otherwise the textFieldShouldReturn(_:)
// won't work and the keyboard will never be hidden.
   priceField.delegate = self
   titleField.delegate = self
   detailsField.delegate = self

   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)
  }

   func textFieldShouldReturn(_ textField: UITextField) -> Bool {
      self.view.endEditing(true)
      return false
   }

 func keyboardWillShow(notification: NSNotification) {
   var translation:CGFloat = 0
   if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
     if detailsField.isEditing{
       translation = CGFloat(-keyboardSize.height)
     }else if priceField.isEditing{
       translation = CGFloat(-keyboardSize.height / 3.8)
     }
   }
    UIView.animate(withDuration: 0.2) {
   self.view.transform = CGAffineTransform(translationX: 0, y: translation)
    }
  }


 func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.2) {
     self.view.transform = CGAffineTransform(translationX: 0, y: 0)
    } 
  }
}

我有几个UITextFields,并希望视图移动不同取决于哪个textField被点击。

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
}

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
}

}

我们对KeyboardWillHideNotification的定义做了一些改变。

此解决方案适用于Swift 4.2:

NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)


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

@objc func keyboardWillHide(_ notification:Notification) {
    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        self.view.frame.origin.y += keyboardSize.height
    }
}

我对初学者的两点建议: 在上面的例子中,有人改变坐标,其他人使用“自动调整蒙版”和其他约束:

正如苹果所说,不要将这三种逻辑混合在一起。 如果你在故事板中有约束,不要尝试改变x/y。这绝对行不通。