如何获得键盘的高度？ （迅速）

不同的iOS设备上的键盘的高度是不同的。 有谁知道我怎样才能以编程方式获得设备的键盘的高度？ 谢谢。

Answer 1

在Swift中：

您可以通过订阅UIKeyboardWillShowNotification通知来获取键盘高度。 （假设你想知道在显示之前的高度是多less）。

像这样的东西：

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

然后你可以像这样访问一些函数中的高度：

Swift 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 } 

Swift 3

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

和：

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

Answer 2

Swift 3.0：

1-在viewWillAppear方法中注册通知：

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

2-被调用的方法：

 func keyboardWillShow(notification: NSNotification) { if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue { let keyboardHeight = keyboardSize.height print(keyboardHeight) } } 

Answer 3

更新Swift 3.0

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

select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，得到不同的结果，这篇文章解释了为什么调用两次。

在Swift 2.2中

Swift 2.2弃用了select器的string，而是引入了新的语法： #selector 。

就像是：

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

select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(_:)) } 

Answer 4

这里较短的版本：

 func keyboardWillShow(notification: NSNotification) { if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() { let keyboardHeight = keyboardSize.height } } 

Answer 5

//第1步：注册通知中心

 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) } 

//第2步： – 这些方法将在键盘出现或隐藏时自动调用

  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 } 

Answer 6

对于苹果UIKit控件包括键盘的代码去顶部https://developer.apple.com/library/content/samplecode/UICatalog/Listings/Swift_UIKitCatalog_TextFieldViewController_swift.html#//apple_ref/doc/uid/DTS40007710-Swift_UIKitCatalog_TextFieldViewController_swift-DontLinkElementID_85可下载的代码这几乎可以用来“开箱即用”;