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

Swift 3更新…

正如其他人所说,你需要在控制器的viewDidLoad()方法中添加通知观察者,如下所示:

NotificationCenter.default.addObserver(forName: .UIKeyboardWillShow, object: nil, queue: nil)
    { notification in
    self.keyboardWillShow(notification)
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardWillHide, object: nil, queue: nil)
    { notification in
    self.keyboardWillHide(notification)
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardDidShow, object: nil, queue: nil)
    { _ in
    self.enableUserInteraction()
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardDidHide, object: nil, queue: nil)
    { _ in
    self.enableUserInteraction()
    }

记得在适当的地方删除你的观察器(我在viewWillDisappear()方法中这样做)

NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidHide, object: nil)

然后,实现你的show和hide方法——注意告诉应用程序忽略交互事件的行(beginIgnoringInteractionEvents)。这很重要,因为如果没有它,用户可能会点击一个字段甚至滚动视图,导致第二次发生移位,从而导致可怕的UI故障。在键盘显示和隐藏之前忽略交互事件将防止这种情况:

func keyboardWillShow(notification: Notification)
    {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
        {
        UIApplication.shared.beginIgnoringInteractionEvents()
        self.view.frame.origin.y -= keyboardSize.height
        // add this line if you are shifting a scrollView, as in a chat application
        self.timelineCollectionView.contentInset.top += keyboardSize.height
        }
    }

func keyboardWillHide(notification: Notification)
    {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
        {
        UIApplication.shared.beginIgnoringInteractionEvents()
        self.view.frame.origin.y += keyboardSize.height
        // add this line if you are shifting a scrollView, as in a chat application
        self.timelineCollectionView.contentInset.top -= keyboardSize.height
        }
    }

最后,重新启用用户交互(记住,这个方法在键盘didShow或didHide之后触发):

func enableUserInteraction()
    {
    UIApplication.shared.endIgnoringInteractionEvents()
    }

其他回答

在这个线程中,一个流行的答案使用了以下代码:

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

用一个静态量来抵消你的视图有一个明显的问题。它在一个设备上看起来很好,但在任何其他尺寸配置上看起来都很糟糕。您需要获取键盘高度并将其用作偏移值。

下面是一种适用于所有设备的解决方案,它可以处理用户在输入时隐藏预测文本字段的边缘情况。

解决方案

下面需要注意的是,我们将self.view.window作为对象参数传入。这将为我们提供来自键盘的数据,比如它的高度!

@IBOutlet weak var messageField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: self.view.window)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: self.view.window)
}

func keyboardWillHide(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!
    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    self.view.frame.origin.y += keyboardSize.height
}

我们将使它在所有设备上看起来都很漂亮,并处理用户添加或删除预测文本字段的情况。

func keyboardWillShow(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!
    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    let offset: CGSize = userInfo[UIKeyboardFrameEndUserInfoKey]!.CGRectValue.size

    if keyboardSize.height == offset.height {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y -= keyboardSize.height
        })
    } else {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y += keyboardSize.height - offset.height
        })
    }
}

删除观察者

不要忘记在离开视图之前删除您的观察器,以防止传输不必要的消息。

override func viewWillDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: self.view.window)
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: self.view.window)
}

根据评论中的问题更新:

如果你有两个或更多的文本字段,你可以检查你的view.frame.origin.y是否为零。

func keyboardWillShow(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!

    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    let offset: CGSize = userInfo[UIKeyboardFrameEndUserInfoKey]!.CGRectValue.size

    if keyboardSize.height == offset.height {
        if self.view.frame.origin.y == 0 {
            UIView.animateWithDuration(0.1, animations: { () -> Void in
                self.view.frame.origin.y -= keyboardSize.height
            })
        }
    } else {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y += keyboardSize.height - offset.height
        })
    }
     print(self.view.frame.origin.y)
}

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
}

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。

func registerForKeyboardNotifications()
    {
        //Keyboard
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWasShown), name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillBeHidden), name: UIKeyboardDidHideNotification, object: nil)


    }
    func deregisterFromKeyboardNotifications(){

        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)

    }
    func keyboardWasShown(notification: NSNotification){

        let userInfo: NSDictionary = notification.userInfo!
        let keyboardInfoFrame = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue()

        let windowFrame:CGRect = (UIApplication.sharedApplication().keyWindow!.convertRect(self.view.frame, fromView:self.view))

        let keyboardFrame = CGRectIntersection(windowFrame, keyboardInfoFrame!)

        let coveredFrame = UIApplication.sharedApplication().keyWindow!.convertRect(keyboardFrame, toView:self.view)

        let contentInsets = UIEdgeInsetsMake(0, 0, (coveredFrame.size.height), 0.0)
        self.scrollViewInAddCase .contentInset = contentInsets;
        self.scrollViewInAddCase.scrollIndicatorInsets = contentInsets;
        self.scrollViewInAddCase.contentSize = CGSizeMake((self.scrollViewInAddCase.contentSize.width), (self.scrollViewInAddCase.contentSize.height))

    }
    /**
     this method will fire when keyboard was hidden

     - parameter notification: contains keyboard details
     */
    func keyboardWillBeHidden (notification: NSNotification) {

        self.scrollViewInAddCase.contentInset = UIEdgeInsetsZero
        self.scrollViewInAddCase.scrollIndicatorInsets = UIEdgeInsetsZero

    }
 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)
 }