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

类似于@Boris的回答,但在Swift 5中:

override func viewDidLoad() {
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}

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

@IBAction func keyboardWillHide(notification: NSNotification) {
    if self.view.frame.origin.y != 0 {
        self.view.frame.origin.y = 0
    }
}

其他回答

这个功能应该在Ios中内置,但是我们需要在外部做。 插入以下代码 *当textField在键盘下时移动视图, *当textField在键盘上方时不移动视图 *在需要时根据键盘的高度移动视图。 这在所有情况下都有效并经过测试。

import UIKit

class NamVcc: UIViewController, UITextFieldDelegate
{
    @IBOutlet weak var NamTxtBoxVid: UITextField!

    var VydTxtBoxVar: UITextField!
    var ChkKeyPadDspVar: Bool = false
    var KeyPadHytVal: CGFloat!

    override func viewDidLoad()
    {
        super.viewDidLoad()

        NamTxtBoxVid.delegate = self
    }

    override func viewWillAppear(animated: Bool)
    {
        NSNotificationCenter.defaultCenter().addObserver(self,
            selector: #selector(TdoWenKeyPadVyd(_:)),
            name:UIKeyboardWillShowNotification,
            object: nil);
        NSNotificationCenter.defaultCenter().addObserver(self,
            selector: #selector(TdoWenKeyPadHyd(_:)),
            name:UIKeyboardWillHideNotification,
            object: nil);
    }

    func textFieldDidBeginEditing(TxtBoxPsgVar: UITextField)
    {
        self.VydTxtBoxVar = TxtBoxPsgVar
    }

    func textFieldDidEndEditing(TxtBoxPsgVar: UITextField)
    {
        self.VydTxtBoxVar = nil
    }

    func textFieldShouldReturn(TxtBoxPsgVar: UITextField) -> Bool
    {
        self.VydTxtBoxVar.resignFirstResponder()
        return true
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?)
    {
        view.endEditing(true)
        super.touchesBegan(touches, withEvent: event)
    }

    func TdoWenKeyPadVyd(NfnPsgVar: NSNotification)
    {
        if(!self.ChkKeyPadDspVar)
        {
            self.KeyPadHytVal = (NfnPsgVar.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().height

            var NonKeyPadAraVar: CGRect = self.view.frame
            NonKeyPadAraVar.size.height -= self.KeyPadHytVal

            let VydTxtBoxCenVal: CGPoint? = VydTxtBoxVar?.frame.origin

            if (!CGRectContainsPoint(NonKeyPadAraVar, VydTxtBoxCenVal!))
            {
                self.ChkKeyPadDspVar = true
                UIView.animateWithDuration(1.0,
                    animations:
                    { self.view.frame.origin.y -= (self.KeyPadHytVal)},
                    completion: nil)
            }
            else
            {
                self.ChkKeyPadDspVar = false
            }
        }

    }

    func TdoWenKeyPadHyd(NfnPsgVar: NSNotification)
    {
        if (self.ChkKeyPadDspVar)
        {
            self.ChkKeyPadDspVar = false
            UIView.animateWithDuration(1.0,
                animations:
                { self.view.frame.origin.y += (self.KeyPadHytVal)},
                completion: nil)
        }
    }

    override func viewDidDisappear(animated: Bool)
    {
        super.viewWillDisappear(animated)
        NSNotificationCenter.defaultCenter().removeObserver(self)
        view.endEditing(true)
        ChkKeyPadDspVar = false
    }
}

|::|有时候视图会向下,在这种情况下使用高度+/- 150:

    NonKeyPadAraVar.size.height -= self.KeyPadHytVal + 150

    { self.view.frame.origin.y -= self.KeyPadHytVal  - 150},
                    completion: nil)

    { self.view.frame.origin.y += self.KeyPadHytVal  - 150},
                completion: nil)

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。

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。

对于Swift 3,我做了一个UIViewController子类,因为我需要在所有的视图控制器中恒定的行为。

class SomeClassVC: UIViewController {

  //MARK: - Lifecycle
  override func viewDidLoad() {
    super.viewDidLoad()

    addKeyboardObservers()
  }

  override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    removeKeyboardObservers()
  }

  //MARK: - Overrides
  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    view.endEditing(true)
  }

  //MARK: - Help
  func addKeyboardObservers() {
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
  }

  func removeKeyboardObservers() {
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: self.view.window)
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: self.view.window)
  }

  func keyboardWillShow(notification: NSNotification) {
    let keyboardHeight = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.height
    UIView.animate(withDuration: 0.1, animations: { () -> Void in
      self.view.window?.frame.origin.y = -1 * keyboardHeight!
      self.view.layoutIfNeeded()
    })
  }

  func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.1, animations: { () -> Void in
      self.view.window?.frame.origin.y = 0
      self.view.layoutIfNeeded()
    })
  }

  func resignTextFieldFirstResponders() {
    for textField in self.view.subviews where textField is UITextField {
      textField.resignFirstResponder()
    }
  }

  func resignAllFirstResponders() {
      view.endEditing(true)
  }
}

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
    }
}