ios 无法在 iOS8 中获得正确的键盘高度值

can't get correct value of keyboard height in iOS8

提问by Eli Braginskiy

I was using this code to determine what is the size of the keyboard :

我正在使用此代码来确定键盘的大小：

- (void)keyboardWillChange:(NSNotification *)notification {
    NSDictionary* keyboardInfo = [notification userInfo];
    NSValue* keyboardFrameBegin = [keyboardInfo valueForKey:UIKeyboardFrameBeginUserInfoKey];
    CGRect keyboardFrameBeginRect = [keyboardFrameBegin CGRectValue];

}

I'm running this in the simulator.

我在模拟器中运行它。

The problem is since iOS 8 this will not give the correct value, if the keyboard suggestions is up or if I push them down I get different (not correct) values.

问题是因为 iOS 8 这不会给出正确的值，如果键盘建议是向上的，或者如果我按下它们，我会得到不同的（不正确的）值。

How can I get the exact size of the keyboard including the keyboard suggestions?

如何获得键盘的确切尺寸，包括键盘建议？

回答by dgangsta

With the introduction of custom keyboards in iOS, this problem becomes a tad more complex.

随着 iOS 中自定义键盘的引入，这个问题变得有点复杂。

In short, the UIKeyboardWillShowNotificationcan get called multiple times by custom keyboard implementations:

简而言之，自定义键盘实现可以多次调用UIKeyboardWillShowNotification：

1. When the Apple systemkeyboard is opened (in portrait)
   • UIKeyboardWillShowNotification is sent with a keyboard height of 224
2. When the Swype keyboardis opened (in portrait):
   • UIKeyboardWillShowNotification is sent with a keyboard height of 0
   • UIKeyboardWillShowNotification is sent with a keyboard height of 216
   • UIKeyboardWillShowNotification is sent with a keyboard height of 256
3. When the SwiftKey keyboardis opened (in portrait):
   • UIKeyboardWillShowNotification is sent with a keyboard height of 0
   • UIKeyboardWillShowNotification is sent with a keyboard height of 216
   • UIKeyboardWillShowNotification is sent with a keyboard height of 259

1. 当Apple 系统键盘打开时（纵向）
   • UIKeyboardWillShowNotification 发送时键盘高度为224
2. 当Swype 键盘打开时（纵向）：
   • UIKeyboardWillShowNotification 发送时键盘高度为0
   • UIKeyboardWillShowNotification 发送时键盘高度为216
   • UIKeyboardWillShowNotification 发送时键盘高度为256
3. 当SwiftKey 键盘打开时（纵向）：
   • UIKeyboardWillShowNotification 发送时键盘高度为0
   • UIKeyboardWillShowNotification 发送时键盘高度为216
   • UIKeyboardWillShowNotification 发送时键盘高度为259

In order to handle these scenarios properly in one code-line, you need to:

为了在一个代码行中正确处理这些场景，您需要：

Register observers against the UIKeyboardWillShowNotificationand UIKeyboardWillHideNotificationnotifications:

针对UIKeyboardWillShowNotification和UIKeyboardWillHideNotification通知注册观察者：

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];    
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];

Create a global variable to track the current keyboard height:

创建一个全局变量来跟踪当前的键盘高度：

CGFloat _currentKeyboardHeight = 0.0f;

Implement keyboardWillShowto react to the current change in keyboard height:

实现keyboardWillShow以响应当前键盘高度的变化：

- (void)keyboardWillShow:(NSNotification*)notification {
   NSDictionary *info = [notification userInfo];
   CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
   CGFloat deltaHeight = kbSize.height - _currentKeyboardHeight; 
   // Write code to adjust views accordingly using deltaHeight
   _currentKeyboardHeight = kbSize.height;
}

NOTE: You may wish to animate the offsetting of views. The infodictionary contains a value keyed by UIKeyboardAnimationDurationUserInfoKey. This value can be used to animate your changes at the same speed as the keyboard being displayed.

注意：您可能希望为视图偏移设置动画。该信息字典包含键的值UIKeyboardAnimationDurationUserInfoKey。此值可用于以与显示键盘相同的速度为您的更改设置动画。

Implement keyboardWillHideto the reset _currentKeyboardHeight and react to the keyboard being dismissed:

将keyboardWillHide实现为重置的 _currentKeyboardHeight 并对被解除的键盘做出反应：

- (void)keyboardWillHide:(NSNotification*)notification {
   NSDictionary *info = [notification userInfo];
   CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
   // Write code to adjust views accordingly using kbSize.height
   _currentKeyboardHeight = 0.0f;
}

回答by souvickcse

Use

用

NSValue* keyboardFrameBegin = [keyboardInfo valueForKey:UIKeyboardFrameEndUserInfoKey];

回答by Mike Gledhill

I also had this issue, until I came across this StackOverflowarticle:

我也有这个问题，直到我遇到这篇StackOverflow文章：

Convert UIKeyboardFrameEndUserInfoKey

转换 UIKeyboardFrameEndUserInfoKey

This shows you how to use the convertRectfunction, to convert the keyboard's size into something usable, but on the screen orientation.

这将向您展示如何使用该convertRect功能，将键盘的大小转换为可用的大小，但在屏幕方向上。

NSDictionary* d = [notification userInfo];
CGRect r = [d[UIKeyboardFrameEndUserInfoKey] CGRectValue];
r = [myView convertRect:r fromView:nil];

Previously, I had an iPad app which used UIKeyboardFrameEndUserInfoKeybut didn'tuse convertRect, and it worked fine.

以前，我有一个 iPad 应用程序，它使用UIKeyboardFrameEndUserInfoKey但没有使用convertRect，并且运行良好。

But with iOS 8, it no longer worked properly. Suddenly, it would report that my keyboard, running on an iPad in landscape mode, was 1024 pixels high.

但是在 iOS 8 中，它不再正常工作。突然，它会报告我的键盘在 iPad 上以横向模式运行，高度为1024 像素。

So now, with iOS 8, it's essential that you use this convertRectfunction.

所以现在，在 iOS 8 中，使用这个convertRect功能是必不可少的。

回答by Avt

The similar to dgangsta'ssolution written in Swift 2.0:

类似于dgangsta用 Swift 2.0 编写的解决方案：

override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)
}

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardWillShow(notification: NSNotification) {
    guard let kbSizeValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
    guard let kbDurationNumber = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber else { return }
    animateToKeyboardHeight(kbSizeValue.CGRectValue().height, duration: kbDurationNumber.doubleValue)
}

func keyboardWillHide(notification: NSNotification) {
    guard let kbDurationNumber = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber else { return }
    animateToKeyboardHeight(0, duration: kbDurationNumber.doubleValue)
}

func animateToKeyboardHeight(kbHeight: CGFloat, duration: Double) {
    // your custom code here
}

回答by Wanbok Choi

I make extensionfor UIViewController

我extension为UIViewController

extension UIViewController {
    func keyboardWillChangeFrameNotification(notification: NSNotification, scrollBottomConstant: NSLayoutConstraint) {
        let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
        let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
        let keyboardBeginFrame = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as! NSValue).CGRectValue()
        let keyboardEndFrame = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()

        let screenHeight = UIScreen.mainScreen().bounds.height
        let isBeginOrEnd = keyboardBeginFrame.origin.y == screenHeight || keyboardEndFrame.origin.y == screenHeight
        let heightOffset = keyboardBeginFrame.origin.y - keyboardEndFrame.origin.y - (isBeginOrEnd ? bottomLayoutGuide.length : 0)

        UIView.animateWithDuration(duration.doubleValue,
            delay: 0,
            options: UIViewAnimationOptions(rawValue: UInt(curve.integerValue << 16)),
            animations: { () in
                scrollBottomConstant.constant = scrollBottomConstant.constant + heightOffset
                self.view.layoutIfNeeded()
            },
            completion: nil
        )
    }
}

You can use like this :

你可以这样使用：

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillChangeFrameNotification:", name: UIKeyboardWillChangeFrameNotification, object: nil)
}

...

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardWillChangeFrameNotification(notification: NSNotification) {
    self.keyboardWillChangeFrameNotification(notification, scrollBottomConstant: inputContainerBottom)
    // Write more to here if you want.
}

回答by Travis M.

There are times when devs need to know the keyboard height before it's actually shown, allowing them pre-layout the interface appropriately.

有时开发人员需要在实际显示之前知道键盘高度，以便他们适当地预先布局界面。

If that's the case, here's an inclusive spec:

如果是这种情况，这里有一个包容性规范：

This includes the quick type bar at the top, since that is on by default in all current versions of iOS.

这包括顶部的快速输入栏，因为它在所有当前版本的 iOS 中默认处于打开状态。

Here is the swift 3 notification setup I used to test this, if anyone needs it:

这是我用来测试的 swift 3 通知设置，如果有人需要的话：

override func viewDidLoad() {
    super.viewDidLoad()
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: .UIKeyboardWillShow, object: nil)
}

func keyboardWillShow(notification: NSNotification) {
    guard let keyboardSize = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
    print("\(keyboardSize)")
}

回答by Petr Syrov

Only one string for swift:

swift 只有一个字符串：

let keyboardSize = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().size

UIKeyboardFrameEndUserInfoKeyalways stores NSValue, so no need to check it.

UIKeyboardFrameEndUserInfoKey总是存储NSValue，所以不需要检查它。

回答by Murray Sagal

In Swift, not in one line...

在 Swift 中，不是在一行中......

self.keyboardDidShowObserver = NSNotificationCenter.defaultCenter().addObserverForName(UIKeyboardDidShowNotification, object: nil, queue: NSOperationQueue.mainQueue(), usingBlock: { (notification) in
        if let userInfo = notification.userInfo, let keyboardFrameValue = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue {
            let keyboardRect = keyboardFrameValue.CGRectValue()
            // keyboardRect.height gives the height of the keyboard
            // your additional code here...
        }
    })

回答by Leo Cavalcante

[notificationCenter addObserverForName:UIKeyboardWillChangeFrameNotification object:nil queue:[NSOperationQueue currentQueue] usingBlock:^(NSNotification * _Nonnull note) {

    float keyboardHeight = [[note.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;

}];

回答by alex-i

I noticed an issue showing when switching between default keyboard and a custom (UIPickerView) keyboard - the custom keyboard would show a 253 height instead of 162, after switching from the default keyboard.

我注意到在默认键盘和自定义 ( UIPickerView) 键盘之间切换时出现的问题- 从默认键盘切换后，自定义键盘将显示 253 高度而不是 162。

What worked in this case was setting autocorrectionType = UITextAutocorrectionTypeNo;for the input field with the custom keyboard.

在这种情况下autocorrectionType = UITextAutocorrectionTypeNo;，使用自定义键盘设置输入字段是有效的。

The issue only occured in iOS 8 (tested on simulator only). It doesn't occur in iOS 9 (simulator or device).

该问题仅在 iOS 8 中出现（仅在模拟器上测试）。它不会发生在 iOS 9（模拟器或设备）中。