问题描述
我有一个scrollView，我想在键盘显示时向上滚动。
I have a scrollView that i want to scroll up when the keyboard is shown.
键盘显示时出现此错误：
I have a crash with this error when the keyboard show :
2014-09-29 14：48：50.738 swrd [1563：472888] - [swrd.EditPhotoViewController keyboardWasShown]：无法识别的选择器发送到实例0x14ed36640
2014-09-29 14:48:50.738 swrd[1563:472888] -[swrd.EditPhotoViewController keyboardWasShown]: unrecognized selector sent to instance 0x14ed36640
这是我的代码，出了什么问题？：
Here is my code, what's wrong ?:
func registerForKeyboardNotifications ()-> Void {
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown", name: UIKeyboardDidShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden", name: UIKeyboardWillHideNotification, object: nil)
}
func deregisterFromKeyboardNotifications () -> Void {
let center: NSNotificationCenter = NSNotificationCenter.defaultCenter()
center.removeObserver(self, name: UIKeyboardDidHideNotification, object: nil)
center.removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWasShown (notification: NSNotification) {
let info : NSDictionary = notification.userInfo!
let keyboardSize = info.objectForKey(UIKeyboardFrameBeginUserInfoKey)?.frame
let insets: UIEdgeInsets = UIEdgeInsetsMake(self.scrollView.contentInset.top, 0, keyboardSize!.height, 0)
self.scrollView.contentInset = insets
self.scrollView.scrollIndicatorInsets = insets
self.scrollView.contentOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentOffset.y + keyboardSize!.height)
}
func keyboardWillBeHidden (notification: NSNotification) {
let info : NSDictionary = notification.userInfo!
let keyboardSize = info.objectForKey(UIKeyboardFrameBeginUserInfoKey)?.frame
let insets: UIEdgeInsets = UIEdgeInsetsMake(self.scrollView.contentInset.top, 0, keyboardSize!.height, 0)
self.scrollView.contentInset = insets
self.scrollView.scrollIndicatorInsets = insets
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
self.registerForKeyboardNotifications()
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(true)
self.deregisterFromKeyboardNotifications()
}
推荐答案
在您的代码中， keyboardWasShown 和 keyboardWasHidden 每个接受一个参数， NSNotification 。您需要使用冒号在 addObserver 中终止选择器，以便传递它。即， keyboardWasShown 和 keyboardWasShown：是不同的选择器。
In your code, keyboardWasShown and keyboardWasHidden each take an argument, the NSNotification. You need to terminate your selectors in addObserver with a colon so that it gets passed. I.e., keyboardWasShown and keyboardWasShown: are different selectors.
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
这篇关于Swift：键盘显示时向上滚动视图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！