Question

我试图在键盘出现时向上移动视图，而在键盘隐藏时向下移动视图。

我遇到的问题是高度似乎有所不同：KBH1输出216，KBH2输出260。

这导致视图被下移得比最初移动的远。

我该如何纠正？

extension UIViewController {

    func addKeyboardFunctions() {

        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboardEx))
       // tap.cancelsTouchesInView = false
        view.addGestureRecognizer(tap)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillDisappear), name: Notification.Name.UIKeyboardWillHide, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillAppear), name: Notification.Name.UIKeyboardWillShow, object: nil)
    }

    @objc func keyboardWillAppear(_ notification: NSNotification) {

        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            if self.view.frame.origin.y == 0{
                self.view.frame.origin.y -= keyboardSize.height
                print("KBH: \(keyboardSize.height)")
            }
        }
    }

    @objc func keyboardWillDisappear(_ notification: NSNotification) {

        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            if self.view.frame.origin.y != 0{
                self.view.frame.origin.y += keyboardSize.height
                print("KBH: \(keyboardSize.height)")
            }
        }
    }

Answer 1

问题是您正在使用UIKeyboardFrameBeginUserInfoKey。

该通知将为您提供开始帧和结束帧，因此您可以相应地移动视图。结束帧将是键盘动画结束的位置，因此它是最终位置。您应该使用此。

我曾经大量使用此扩展程序，我认为它是用于Swift 2

func getKeyboardHeight(notification: NSNotification) -> CGFloat {
    let userInfo = notification.userInfo
    let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue
    return keyboardSize.CGRectValue().height
}

您应该能够针对Swift 4进行更新，但是最重要的部分是使用结束帧而不是开始

使用键盘快速移动视图

1 个答案: