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

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)
}

其他回答

这是我的解决方案(实际上这段代码是在你的视图中有几个文本字段的情况下,这也适用于当你有一个文本字段的情况下)

class MyViewController: UIViewController, UITextFieldDelegate {

@IBOutlet weak var firstTextField: UITextField!
@IBOutlet weak var secondTextField: UITextField!

var activeTextField: UITextField!
var viewWasMoved: Bool = false


override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}

override func viewDidDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func textFieldDidBeginEditing(textField: UITextField) {
    self.activeTextField = textField
}

func textFieldDidEndEditing(textField: UITextField) {
    self.activeTextField = nil
}

func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}


func keyboardWillShow(notification: NSNotification) {

    let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()

    var aRect: CGRect = self.view.frame
    aRect.size.height -= keyboardSize!.height

    let activeTextFieldRect: CGRect? = activeTextField?.frame
    let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin

    if (!CGRectContainsPoint(aRect, activeTextFieldOrigin!)) {
        self.viewWasMoved = true
        self.view.frame.origin.y -= keyboardSize!.height
    } else {
        self.viewWasMoved = false
    }
}

func keyboardWillHide(notification: NSNotification) {
    if (self.viewWasMoved) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
            self.view.frame.origin.y += keyboardSize.height
        }
    }
}

@Boris的解决方案非常好,但观点有时会被破坏。

为了实现完美的对齐,请使用下面的代码

override func viewDidLoad() {
super.viewDidLoad()            
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)}

功能:

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

And,

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

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
    }
}

对我有用

override func viewDidLoad() {

        super.viewDidLoad()

        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)
}

 var isScroll = false


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

斯威夫特4.1

 override func viewDidLoad() {
    super.viewDidLoad()            
    NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(ViewController.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   //can adjust as keyboardSize.height-(any number 30 or 40)
        }
    }        
}

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