ios Swift 3 NSNotificationCenter 键盘将显示/隐藏
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/37825327/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Swift 3 NSNotificationCenter Keyboardwillshow/hide
提问by RubberDucky4444
I have a piece of code that worked in Swift 2 and I tried using Xcode to update the code to the newest version and I fixed everything except two issues.
我有一段在 Swift 2 中工作的代码，我尝试使用 Xcode 将代码更新到最新版本，除两个问题外，我修复了所有问题。
I have this code :
我有这个代码：
let loginvc: LoginVC = self.storyboard?.instantiateViewController(withIdentifier: "LoginVC") as! LoginVC
NotificationCenter.defaultCenter().addObserver(self, selector: #selector(LoginViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
NotificationCenter.defaultCenter().addObserver(self, selector: #selector(LoginViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
That pairs along with this:
与此配对：
func keyboardWillShow(notification: NSNotification) {
constraint.constant = -100
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded()
}
}
func keyboardWillHide(notification: NSNotification) {
constraint.constant = 25
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded()
}
}
On the first part I now get an error saying
在第一部分，我现在收到一条错误消息
Type 'LoginViewController' has no member 'keyboardWillShow/Hide'
类型“LoginViewController”没有成员“keyboardWillShow/Hide”
I don't understand why it is not seeing the method underneath.
我不明白为什么它没有看到下面的方法。
Does anybody know a solution to this issue?
有人知道这个问题的解决方案吗？
采纳答案by Lucas
Check out the updated Swift Programming Language book. Pages 1027 and 1028 are what you're looking for. It should be something like this:
查看更新的Swift 编程语言书籍。第 1027 和 1028 页正是您要查找的内容。它应该是这样的：
func keyboardWillHide(_ notification: NSNotification) {…
Notice the additional underscore above. Also:
请注意上面的附加下划线。还：
#selector(LoginViewController.keyboardWillHide(_:))
You also might need to add @objc(keyboardWillHideWithNotification:)to your class.
您可能还需要添加@objc(keyboardWillHideWithNotification:)到您的班级。
回答by Ricardo Isidro
On Swift 4.2, addObserver name for NSNotificationCenter changed as well:
在 Swift 4.2 上，NSNotificationCenter 的 addObserver 名称也发生了变化：
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardDidShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardDidHideNotification, object: nil)
回答by Harshad Patel
Use that code that's work on swift3
使用适用于 swift3 的代码
You can use your ViewController (e.g, loginvc) to add notification
您可以使用您的 ViewController（例如，loginvc）来添加通知
let loginvc : LoginVC = self.storyboard?.instantiateViewController(withIdentifier: "LoginVC") as! LoginVC
NotificationCenter.default.addObserver(self,
selector: #selector(loginvc.keyboardWillShow(notification:)),
name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self,
selector: #selector(loginvc.keyboardWillHide(notification:)),
name: NSNotification.Name.UIKeyboardWillHide, object: nil)
Then add keyboard hide and show method
然后添加键盘隐藏和显示方法
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
print("Show")
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
print("Hide")
}
}
回答by Pablo Ruan
NSNotificationCenter have things alter for get show keyboard:
NSNotificationCenter 有一些改变以获得显示键盘：
NotificationCenter.default.addObserver(self, selector: #selector(NovaVisitaVC.abreTeclado(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(NovaVisitaVC.abreTeclado(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
