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

斯威夫特5.0:

经过4-5个小时的战斗,我得到了一个简单的扩展UIViewController与简单的代码,就像魅力

*当TextField在键盘上方时,视图不应该移动

*不需要设置常量值为NSLayoutConstraint

*无需第三方库

*无需动画代码

*适用于tableview

*这适用于自动布局/自动调整大小

extension UIViewController {
    func addKeyboardObserver() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotifications(notification:)),
                                               name: UIResponder.keyboardWillChangeFrameNotification,
                                               object: nil)
    }

    func removeKeyboardObserver(){
        NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }

    // This method will notify when keyboard appears/ dissapears
    @objc func keyboardNotifications(notification: NSNotification) {

        var txtFieldY : CGFloat = 0.0  //Using this we will calculate the selected textFields Y Position
        let spaceBetweenTxtFieldAndKeyboard : CGFloat = 5.0 //Specify the space between textfield and keyboard


        var frame = CGRect(x: 0, y: 0, width: 0, height: 0)
        if let activeTextField = UIResponder.currentFirst() as? UITextField ?? UIResponder.currentFirst() as? UITextView {
            // Here we will get accurate frame of textField which is selected if there are multiple textfields
            frame = self.view.convert(activeTextField.frame, from:activeTextField.superview)
            txtFieldY = frame.origin.y + frame.size.height
        }

        if let userInfo = notification.userInfo {
            // here we will get frame of keyBoard (i.e. x, y, width, height)
            let keyBoardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
            let keyBoardFrameY = keyBoardFrame!.origin.y
            let keyBoardFrameHeight = keyBoardFrame!.size.height

            var viewOriginY: CGFloat = 0.0
            //Check keyboards Y position and according to that move view up and down
            if keyBoardFrameY >= UIScreen.main.bounds.size.height {
                viewOriginY = 0.0
            } else {
                // if textfields y is greater than keyboards y then only move View to up
                if txtFieldY >= keyBoardFrameY {

                    viewOriginY = (txtFieldY - keyBoardFrameY) + spaceBetweenTxtFieldAndKeyboard

                    //This condition is just to check viewOriginY should not be greator than keyboard height
                    // if its more than keyboard height then there will be black space on the top of keyboard.
                    if viewOriginY > keyBoardFrameHeight { viewOriginY = keyBoardFrameHeight }
                }
            }

            //set the Y position of view
            self.view.frame.origin.y = -viewOriginY
        }
    }
}

添加这个扩展的UIResponder得到哪个TextField被选中

extension UIResponder {

    static weak var responder: UIResponder?

    static func currentFirst() -> UIResponder? {
        responder = nil
        UIApplication.shared.sendAction(#selector(trap), to: nil, from: nil, for: nil)
        return responder
    }

    @objc private func trap() {
        UIResponder.responder = self
    }
}

然后在你的任何ViewController中使用这个

   override func viewWillAppear(_ animated: Bool) {
        self.addKeyboardObserver()
    }

    override func viewWillDisappear(_ animated: Bool) {
        self.removeKeyboardObserver()
    }

在func viewWillAppear中注册这个通知(_ animated: Bool) 在func中注销此通知viewWillDisappear(_ animated:Bool) 下载演示文件

其他回答

如果你在同一个VC中有2个或更多的文本字段,用户点击其中一个,然后点击另一个,不调用keyboardWillHide函数,视图会再向上一次,这是不必要的,因为你会有键盘,一个空格,它有键盘的高度,然后视图,使用我编辑的答案中的代码:

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

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

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

为了解决这个问题,将两个函数"KeyboardWillShow/Hide"替换为:

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

func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        if view.frame.origin.y != 0 {
            self.view.frame.origin.y += keyboardSize.height
        }
    }
}

我改进了其中一个答案,使它与不同的键盘和不同的文本视图/字段在一个页面上工作:

添加观察员:

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

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)

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

func keyboardWillHide() {
    self.view.frame.origin.y = 0
}

func keyboardWillChange(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        if YOURTEXTVIEW.isFirstResponder {
            self.view.frame.origin.y = -keyboardSize.height
        }
    }
}

删除观察员:

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

    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}

不是广告、促销或垃圾邮件,只是一个很好的解决方案。我知道这个问题有近30个答案,我很震惊,居然没有人提到过这个美丽的GitHub项目,它为你做了这一切,甚至更好。所有的答案只是向上移动视图。我刚刚用这个IQKeyboardManager解决了我所有的问题。它有13000多颗恒星。 如果你使用swift,只需将此添加到你的podfile中

pod 'IQKeyboardManagerSwift'

然后在你的AppDelegate.swift中导入IQKeyboardManagerSwift

import IQKeyboardManagerSwift

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

      IQKeyboardManager.shared.enable = true // just add this line

      return true
    }
}

添加一行IQKeyboardManager.shared.enable = true来启用它 如果您要进行生产,那么这个解决方案是必须的。

最简单的方法,甚至不需要任何代码:

下载KeyboardLayoutConstraint.swift并将文件添加(拖放)到你的项目中,如果你还没有使用Spring动画框架的话。 在你的故事板中,为视图或文本字段创建一个底部约束,选择约束(双击它),在标识检查器中,将其类从NSLayoutConstraint更改为KeyboardLayoutConstraint。 完成了!

物体会随着键盘同步自动移动。

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
    }
}