如何获得键盘的高度？

Question

不同的iOS设备上的键盘高度不同。有人知道我如何以编程方式获取设备键盘的高度吗？

Answer 1

在Swift中：

您可以通过订阅UIKeyboardWillShowNotification通知来获取键盘高度。（假设您想知道显示的高度是多少）。

像这样：

迅捷2

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)

迅捷3

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: NSNotification.Name.UIKeyboardWillShow,
    object: nil
)

斯威夫特4

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: UIResponder.keyboardWillShowNotification,
    object: nil
)

然后，您可以使用以下keyboardWillShow功能访问高度：

迅捷2

func keyboardWillShow(notification: NSNotification) {
    let userInfo: NSDictionary = notification.userInfo!
    let keyboardFrame: NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
    let keyboardRectangle = keyboardFrame.CGRectValue()
    let keyboardHeight = keyboardRectangle.height
}

迅捷3

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

斯威夫特4

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}