我一直在试图添加一些代码来移动我的视图，当键盘出现，但是，我有问题，试图将Objective-C的例子翻译成Swift。我已经取得了一些进展，但我被困在一条线。
这是我一直在关注的两个教程/问题：
How to move content of UIViewController upwards as Keypad appears using Swift
http://www.ioscreator.com/tutorials/move-view-when-keyboard-appears
这里是我目前有的代码：
override func viewWillAppear(animated: Bool) {
NSNotificationCenter.defaultCenter().addObserver(self,selector: "keyboardWillShow:",name: UIKeyboardWillShowNotification,object: nil)
NSNotificationCenter.defaultCenter().addObserver(self,selector: "keyboardWillHide:",name: UIKeyboardWillHideNotification,object: nil)
}
override func viewWillDisappear(animated: Bool) {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardWillShow(notification: NSNotification) {
var keyboardSize = notification.userInfo(valueForKey(UIKeyboardFrameBeginUserInfoKey))
UIEdgeInsets(top: 0,left: 0,bottom: keyboardSize.height,right: 0)
let frame = self.budgetEntryView.frame
frame.origin.y = frame.origin.y - keyboardSize
self.budgetEntryView.frame = frame
}
func keyboardWillHide(notification: NSNotification) {
//
}
目前，我在这行上得到一个错误：
var keyboardSize = notification.userInfo(valueForKey(UIKeyboardFrameBeginUserInfoKey))
如果有人可以让我知道这行代码应该是什么，我应该设法弄清楚其余的自己。
在你的线有一些问题
var keyboardSize = notification.userInfo(valueForKey(UIKeyboardFrameBeginUserInfoKey))
> notification.userInfo返回一个可选的字典[NSObject：AnyObject]？
因此在访问其值之前必须将其解包。
> Objective-C NSDictionary映射到一个Swift本地词典，所以你必须
使用字典下标语法(dict [key])来访问值。
>该值必须转换为NSValue，以便可以对其调用CGRectValue。
所有这一切都可以通过可选的赋值，可选的链接和
可选转换：
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = UIEdgeInsets(top: 0,right: 0)
// ...
} else {
// no UIKeyboardFrameBeginUserInfoKey entry in userInfo
}
} else {
// no userInfo dictionary in notification
}
或在一个步骤：
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = UIEdgeInsets(top: 0,right: 0)
// ...
}
Swift 3.0.1(Xcode 8.1)的更新：
if let userInfo = notification.userInfo {
if let keyboardSize = userInfo[UIKeyboardFrameBeginUserInfoKey] as? CGRect {
let contentInsets = UIEdgeInsets(top: 0,right: 0)
// ...
} else {
// no UIKeyboardFrameBeginUserInfoKey entry in userInfo
}
} else {
// no userInfo dictionary in notification
}
或在一个步骤：
if let keyboardSize = notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? CGRect {
let contentInsets = UIEdgeInsets(top: 0,right: 0)
// ...
}
