如何获得键盘的高度？

Answers:

217

在Swift中：

您可以通过订阅UIKeyboardWillShowNotification通知来获取键盘高度。（假设您想知道显示的高度是多少）。

像这样：

迅捷2

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)

迅捷3

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: NSNotification.Name.UIKeyboardWillShow,
    object: nil
)

斯威夫特4

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

然后，您可以在keyboardWillShow函数中访问高度，如下所示：

迅捷2

func keyboardWillShow(notification: NSNotification) {
    let userInfo: NSDictionary = notification.userInfo!
    let keyboardFrame: NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
    let keyboardRectangle = keyboardFrame.CGRectValue()
    let keyboardHeight = keyboardRectangle.height
}

迅捷3

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

斯威夫特4

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}
— 鹏
source
我不明白为什么这里的人think-in-g.net/ghawk/blog/2012/09/…检查isPortrait。keyboardRectangle.height是否在所有方向上仍然正确？
— 安东·特罗帕斯科
5
是的，迅速3混乱了。每次都赋予不同的价值
— Mahesh Agrawal
NotificationCenter.default.addObserver（自身，选择器：#selector（keyboardWillShow），名称：.UIKeyboardWillShow，对象：nil）是正确的语法
— ShinyX 2015年
如果您已经可以看到键盘，并且旋转设备该怎么办？如何找到新的键盘高度？
— Khoury
1
将其用于Swift 4：UIResponder.keyboardWillShowNotification以名称命名
— George_E '18
63

Swift 3.0和Swift 4.1

1-在viewWillAppear方法中注册通知：

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

2-调用方法：

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight = keyboardSize.height
        print(keyboardHeight)
    }
}
— fs_tigre
source
3
这可行，您也可以将keyboardWillShow参数的类型Notification设为使其更符合Swift 3.0。
— bfich
1
当我们调用函数keyBoardWillShow（）时，究竟将什么作为参数？我已经在viewDidLoad中添加了第一行，并且在类中添加了函数...但是我不确定如何调用它哈哈
— VDog
1
@VDog你不叫它，iOS设备将它称为显示键盘时
— 耶利米·纳恩
4
注册通知viewDidLoad不是一个好主意：您将匹配的removeObserver呼叫放在哪里，以便当不再显示此VC时，它将停止获取通知？最好将通知注册放入viewWillAppear，然后removeObserverviewWillDisappear
— 再拨
5
您需要将“ UIKeyboardFrameBeginUserInfoKey”更改为“ UIKeyboardFrameEndUserInfoKey”，因为在您的示例中，您通常可以将高度设为零。详细信息：stackoverflow.com/questions/45689664/…–
— andreylanadelrey
26

Swift 4和约束

在表格视图中，添加相对于底部安全区域的底部约束。在我的情况下，约束称为tableViewBottomLayoutConstraint。

@IBOutlet weak var tableViewBottomLayoutConstraint: NSLayoutConstraint!

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

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillAppear(notification:)), name: .UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillDisappear(notification:)), name: .UIKeyboardWillHide, object: nil)
}

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

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

@objc 
func keyboardWillAppear(notification: NSNotification?) {

    guard let keyboardFrame = notification?.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else {
        return
    }

    let keyboardHeight: CGFloat
    if #available(iOS 11.0, *) {
        keyboardHeight = keyboardFrame.cgRectValue.height - self.view.safeAreaInsets.bottom
    } else {
        keyboardHeight = keyboardFrame.cgRectValue.height
    }

    tableViewBottomLayoutConstraint.constant = keyboardHeight
}

@objc 
func keyboardWillDisappear(notification: NSNotification?) {
    tableViewBottomLayoutConstraint.constant = 0.0
}
— 爱德华多·伊里亚斯
source
2
这些问题中任何一个的第一个答案都考虑到了安全区域。谢谢！
— Zach Nicoll
20

更新Swift 4.2

private func setUpObserver() {
    NotificationCenter.default.addObserver(self, selector: .keyboardWillShow, name: UIResponder.keyboardWillShowNotification, object: nil)
}

选择器方法：

@objc fileprivate func keyboardWillShow(notification:NSNotification) {
    if let keyboardRectValue = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight = keyboardRectValue.height
    }
}

延期：

private extension Selector {
    static let keyboardWillShow = #selector(YourViewController.keyboardWillShow(notification:)) 
}

更新Swift 3.0

private func setUpObserver() {
    NotificationCenter.default.addObserver(self, selector: .keyboardWillShow, name: .UIKeyboardWillShow, object: nil)
}

选择器方法：

@objc fileprivate func keyboardWillShow(notification:NSNotification) {
    if let keyboardRectValue = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight = keyboardRectValue.height
    }
}

延期：

private extension Selector {
    static let keyboardWillShow = #selector(YourViewController.keyboardWillShow(notification:)) 
}

小费

UIKeyboardDidShowNotification或UIKeyboardWillShowNotification可能会调用两次并得到不同的结果，本文解释了为什么调用两次。

在Swift 2.2中

Swift 2.2不赞成使用字符串作为选择器，而是引入了新语法：#selector。

就像是：

private func setUpObserver() {

    NSNotificationCenter.defaultCenter().addObserver(self, selector: .keyboardWillShow, name: UIKeyboardWillShowNotification, object: nil)
}

选择器方法：

@objc private func keyboardWillShow(notification:NSNotification) {

    let userInfo:NSDictionary = notification.userInfo!
    let keyboardFrame:NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
    let keyboardRectangle = keyboardFrame.CGRectValue()
    let keyboardHeight = keyboardRectangle.height
    editorBottomCT.constant = keyboardHeight
}

延期：

    private extension Selector {

    static let keyboardWillShow = #selector(YourViewController.keyboardWillShow(_:)) 
}
— 杰西
source
3
不要忘记删除deinit中的观察者，例如：NSNotificationCenter.defaultCenter（）。removeObserver（self）
— tapmonkey
11

较短的版本在这里：

func keyboardWillShow(notification: NSNotification) {

        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            let keyboardHeight = keyboardSize.height
        }
}
— 亚历山大
source
1
您在通知下为keyboardWillShow传递了什么参数？
— VDog '17
很难说，我是在回复海报的代码块...但是它与此行相对应（让userInfo：NSDictionary = notification.userInfo！）
— Alessign
6

斯威夫特4。

最简单的方法

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

func keyboardWillShow(notification: NSNotification) {  

      if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
             let keyboardHeight : Int = Int(keyboardSize.height)
             print("keyboardHeight",keyboardHeight) 
      }

}
— ZAFAR007
source
4

迅捷5

override func viewDidLoad() {
    //  Registering for keyboard notification.
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
}


/*  UIKeyboardWillShowNotification. */
    @objc internal func keyboardWillShow(_ notification : Notification?) -> Void {
        
        var _kbSize:CGSize!
        
        if let info = notification?.userInfo {

            let frameEndUserInfoKey = UIResponder.keyboardFrameEndUserInfoKey
            
            //  Getting UIKeyboardSize.
            if let kbFrame = info[frameEndUserInfoKey] as? CGRect {
                
                let screenSize = UIScreen.main.bounds
                
                //Calculating actual keyboard displayed size, keyboard frame may be different when hardware keyboard is attached (Bug ID: #469) (Bug ID: #381)
                let intersectRect = kbFrame.intersection(screenSize)
                
                if intersectRect.isNull {
                    _kbSize = CGSize(width: screenSize.size.width, height: 0)
                } else {
                    _kbSize = intersectRect.size
                }
                print("Your Keyboard Size \(_kbSize)")
            }
        }
    }
— 维维克
source
2

//步骤1：-注册NotificationCenter

ViewDidLoad() {

   self.yourtextfield.becomefirstresponder()

   // Register your Notification, To know When Key Board Appears.
    NotificationCenter.default.addObserver(self, selector: #selector(SelectVendorViewController.keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)

   // Register your Notification, To know When Key Board Hides.
    NotificationCenter.default.addObserver(self, selector: #selector(SelectVendorViewController.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

//步骤2：-当出现或隐藏键盘时，将自动调用这些方法

    func keyboardWillShow(notification:NSNotification) {
        let userInfo:NSDictionary = notification.userInfo! as NSDictionary
        let keyboardFrame:NSValue = userInfo.value(forKey: UIKeyboardFrameEndUserInfoKey) as! NSValue
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
        tblViewListData.frame.size.height = fltTblHeight-keyboardHeight
    }

    func keyboardWillHide(notification:NSNotification) {
        tblViewListData.frame.size.height = fltTblHeight
    }
— 神经
source
1

ZAFAR007的方法已针对Xcode 10中的Swift 5更新

override func viewDidLoad() {
    super.viewDidLoad()

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

}




@objc func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight : Int = Int(keyboardSize.height)
        print("keyboardHeight",keyboardHeight)
    }

}
— PTDog94
source
在程序执行期间首次调用后，这会产生不同的高度。
— 布兰登·斯蒂利塔诺
0

我必须这样做。这有点黑客。不建议。
但是我发现这很有帮助，
我做了扩展和结构

ViewController扩展+结构

import UIKit
struct viewGlobal{
    static var bottomConstraint : NSLayoutConstraint = NSLayoutConstraint()
}

extension UIViewController{ //keyboardHandler
 func hideKeyboardWhenTappedAround() {
    let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
    tap.cancelsTouchesInView = false
    view.addGestureRecognizer(tap)
 }
 func listenerKeyboard(bottomConstraint: NSLayoutConstraint) {
    viewGlobal.bottomConstraint = bottomConstraint
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
    // Register your Notification, To know When Key Board Hides.
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
 }
 //Dismiss Keyboard
 @objc func dismissKeyboard() {
    view.endEditing(true)
 }
 @objc func keyboardWillShow(notification:NSNotification) {
    let userInfo:NSDictionary = notification.userInfo! as NSDictionary
    let keyboardFrame:NSValue = userInfo.value(forKey: UIResponder.keyboardFrameEndUserInfoKey) as! NSValue
    let keyboardRectangle = keyboardFrame.cgRectValue
    let keyboardHeight = keyboardRectangle.height
    UIView.animate(withDuration: 0.5){
        viewGlobal.bottomConstraint.constant = keyboardHeight
    }
 }

 @objc func keyboardWillHide(notification:NSNotification) {
    UIView.animate(withDuration: 0.5){
        viewGlobal.bottomConstraint.constant = 0
    }
 }
}

用法：
获得最底层约束

@IBOutlet weak var bottomConstraint: NSLayoutConstraint! // default 0

调用viewDidLoad（）内部的函数

override func viewDidLoad() {
    super.viewDidLoad()

    hideKeyboardWhenTappedAround()
    listenerKeyboard(bottomConstraint: bottomConstraint)

    // Do any additional setup after loading the view.
}

希望能有所帮助。
-你的键盘现在将自动关闭，当文本字段的用户水龙头之外，并
- 这将推动所有以键盘上方时，键盘出现。
-您也可以在需要时使用dismissKeyboard（）

— 穆罕默德·阿斯拉夫（Muhammad Asyraf）
source
0

我用下面的代码，

override func viewDidLoad() {
    super.viewDidLoad()
    self.registerObservers()
}

func registerObservers(){

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

}

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

@objc func keyboardWillAppear(notification: Notification){
    if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
        self.view.transform = CGAffineTransform(translationX: 0, y: -keyboardHeight)
    }
}

@objc func keyboardWillHide(notification: Notification){
        self.view.transform = .identity
}
— 萨扎德（Sazzad Hissain Khan）
source
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