监听键盘起落 下面是可以监听到得四种状态
UIKeyboardWillShowNotification: String
UIKeyboardDidShowNotification: String
UIKeyboardWillHideNotification: String
UIKeyboardDidHideNotification: String
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillAppear:", name: UIKeyboardWillShowNotification, object: nil) NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillDisappear:", name:UIKeyboardWillHideNotification, object: nil)
func keyboardWillAppear(notification: NSNotification) {
// 获取键盘信息
let keyboardinfo = notification.userInfo![UIKeyboardFrameBeginUserInfoKey]
let keyboardheight:CGFloat = (keyboardinfo?.CGRectValue.size.height)!
print("键盘弹起")
print(keyboardheight)
}
func keyboardWillDisappear(notification:NSNotification){
print("键盘落下")
}
原文：http://www.cnblogs.com/torrescx/p/5332673.html