xcode 如何以编程方式在 iOS 中获得导航栏高度
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How to get a navigation bar hight in iOS programatically
提问by sritharan
I have to move up my view when keyboardwillshownthen it back to it's normal place when keyboard will hide
keyboardwillshown当键盘将隐藏时，我必须向上移动我的视图然后它回到它的正常位置
Actually I have used this code on viewdidloadmethod:
实际上我在viewdidload方法上使用了这个代码：
override func viewDidLoad() {
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)
}
Here is the method which I used for move up and down
这是我用来上下移动的方法
func keyboardWillShow(notification:NSNotification){
print("keyboardwillshow")
let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
self.view.frame = CGRectMake(0.0, -keyboardSize!.size.height + (self.navigationController?.navigationBar.frame.size.height)! + 20 , self.view.frame.size.width, self.view.frame.size.height )
}
func keyboardWillHide(notification:NSNotification){
self.view.frame = CGRectMake(0.0,(self.navigationController?.navigationBar.frame.size.height)!, self.view.frame.size.width, self.view.frame.size.height)
// self.view.frame.origin.y += 350
}
While I run this program, it will show a run time error that is
当我运行这个程序时，它会显示一个运行时错误
unexpected found a nil while unwrapping
在解包时意外发现一个 nil
Please help me fix this.
请帮我解决这个问题。
回答by Krunal
With iPhone-X, height of top bar (navigation bar + status bar) is changed (increased).
使用 iPhone-X，顶部栏（导航栏 + 状态栏）的高度发生了变化（增加）。
Try this if you want exact height of top bar (both navigation bar + status bar):
如果您想要顶部栏的确切高度（导航栏 + 状态栏），请尝试此操作：
Objective-C
目标-C
CGFloat topbarHeight = ([UIApplication sharedApplication].statusBarFrame.size.height +
(self.navigationController.navigationBar.frame.size.height ?: 0.0));
Swift 4
斯威夫特 4
let topBarHeight = UIApplication.shared.statusBarFrame.size.height +
(self.navigationController?.navigationBar.frame.height ?? 0.0)
For ease, try this UIViewController extension
为方便起见，试试这个 UIViewController 扩展
extension UIViewController {
/**
* Height of status bar + navigation bar (if navigation bar exist)
*/
var topbarHeight: CGFloat {
return UIApplication.shared.statusBarFrame.size.height +
(self.navigationController?.navigationBar.frame.height ?? 0.0)
}
}
Swift 3
斯威夫特 3
let topBarHeight = UIApplication.sharedApplication().statusBarFrame.size.height +
(self.navigationController?.navigationBar.frame.height ?? 0.0)
回答by Ram Madhavan
In Swift 3You will get the navigation bar height by using the following way:
在Swift 3 中，您将使用以下方式获取导航栏高度：
self.navigationController?.navigationBar.intrinsicContentSize.height
回答by Sourabh Sharma
let navigationBarHeight: CGFloat = self.navigationController!.navigationBar.frame.height
回答by Pradeep K
You should protect your code against nil values this way. it will also help in using your view controllers inside navigation controllers and outside.
您应该通过这种方式保护您的代码免受 nil 值的影响。它还有助于在导航控制器内部和外部使用您的视图控制器。
func keyboardWillShow(notification:NSNotification){
print("keyboardwillshow")
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
if let navBarHeight = self.navigationController?.navigationBar.frame.size.height {
self.view.frame = CGRectMake(0.0, -keyboardSize.size.height + navBarHeight + 20 , self.view.frame.size.width, self.view.frame.size.height )
} else {
print("could not get navbar height")
self.view.frame = CGRectMake(0.0, -keyboardSize.size.height + 20 , self.view.frame.size.width, self.view.frame.size.height )
}
} else {
print("no keyboard size property")
}
}
