在iOS設備中出現鍵盤時滑動UIView

Question

我知道關於鍵盤出現在iOS上時滑動UIView的問題也很多。 但是，我的實現似乎有一個我未曾提及的問題。 發生幻燈片動畫時，它不是從屏幕頂部開始，而是我從較低的原點開始，然后又向上移動到屏幕頂部。

這是我為實現此上滑行為而創建的類擴展。

public extension UIViewController {

    private dynamic func keyboardWillShow(sender: NSNotification) {
        if view.frame.origin.y == 0 {
            slideViewVerticallyForKeyboardHeight(sender, directionUp: true)
        }
    }

    private dynamic func keyboardWillHide(sender: NSNotification) {
        if view.frame.origin.y < 0 {
            slideViewVerticallyForKeyboardHeight(sender, directionUp: false)
        }
    }

    private func slideViewVerticallyForKeyboardHeight(notification: NSNotification, directionUp: Bool) {
        UIView.beginAnimations(nil, context: nil)
        let keyboardHeight: CGFloat = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().height ?? 0.0
        let animationDuration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey]?.doubleValue ?? 0.0
        let animationCurve: Int = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey]?.integerValue ?? 0
        UIView.setAnimationDuration(animationDuration)
        UIView.setAnimationCurve(UIViewAnimationCurve(rawValue: animationCurve)!)
        UIView.setAnimationBeginsFromCurrentState(true)

        var newFrameRect = view.frame
        if directionUp {
            newFrameRect.origin.y -= keyboardHeight
            newFrameRect.size.height += keyboardHeight
        } else {
            newFrameRect.origin.y += keyboardHeight
            newFrameRect.size.height -= keyboardHeight
        }
        view.frame = newFrameRect
        UIView.commitAnimations()
    }

    public func registerViewSlideOnKeyobard() {
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    public func unregisterViewSlideOnKeyboard() {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }
}

我不確定我缺少什么。 看我的view.frame值，我有一個負的origin.y，正如我期望的那樣。 有人看到我想念的東西嗎？

編輯 ：aimak用戶提出了一個非常明智的建議，即我將動畫更改為（不推薦使用）塊調用版本。 有趣的是，動畫仍然被破壞，但是方式不同。 這是經過修改的代碼，以及有關最新動畫調用發生的情況的屏幕截圖。

private func slideViewVerticallyForKeyboardHeight(notification: NSNotification, directionUp: Bool) {
    UIView.beginAnimations(nil, context: nil)
    let keyboardHeight: CGFloat = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().height ?? 0.0
    let animationDuration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey]?.doubleValue ?? 0.0
    let animationCurve: UIViewAnimationCurve = UIViewAnimationCurve(rawValue: notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey]?.integerValue ?? 0)!
    var newFrameRect = view.frame
    if directionUp {
        newFrameRect.origin.y -= keyboardHeight
        newFrameRect.size.height += keyboardHeight
    } else {
        newFrameRect.origin.y += keyboardHeight
        newFrameRect.size.height -= keyboardHeight
    }

    UIView.animateWithDuration(animationDuration, delay: 0, options: animationCurve.toOptions(), animations: {
            self.view.frame = newFrameRect
        }, completion: nil)
}

Answer 1

這可能無法完全幫助您，但是自iOS 4+起不鼓勵使用這些動畫方法：

不鼓勵在iOS 4.0及更高版本中使用此方法。 您應該改用基於塊的動畫方法來指定動畫。

參考： https : //developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/#//apple_ref/occ/clm/UIView/commitAnimations

您是否嘗試過基於塊的API？

編輯：這是自動布局的問題！

好的，我想我知道了：您是否使用自動版式？ 如果是這樣，則UIViewController.view的子視圖可能具有view.top = 0的約束，並且該約束永遠不會被破壞。 如果要獲得所需的動畫，請考慮：1.將每個子視圖嵌入scrollView中（然后為contentOffet.y動畫），或2.刪除/編輯view.top約束。

Answer 2

正如aimak所指出的那樣，問題在於我使用的是AutoLayout，並且約束覆蓋了我對框架所做的修改。 為了解決這個問題，我將所有內容移到了滾動視圖中。 現在，我利用滾動scrollview來在鍵盤顯示時偏移。

這是我必須提供滾動行為的幫助器類。 請注意，我現在通過了滾動視圖。

public class KeyboardScrollViewHelper {

    private var scrollView: UIScrollView?
    private var isScrolled = false

    private dynamic func keyboardWillShow(sender: NSNotification) {
        guard !isScrolled else {
            return
        }

        slideViewVerticallyForKeyboardHeight(sender, directionUp: true)
    }

    private dynamic func keyboardWillHide(sender: NSNotification) {
        guard isScrolled else {
            return
        }

        slideViewVerticallyForKeyboardHeight(sender, directionUp: false)
    }

    private func slideViewVerticallyForKeyboardHeight(notification: NSNotification, directionUp: Bool) {

        guard let scrollView = self.scrollView else {
            return
        }

        let keyboardHeight: CGFloat = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue().height ?? 0.0
        let animationDuration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey]?.doubleValue ?? 0.0
        let animationCurve: UIViewAnimationCurve = UIViewAnimationCurve(rawValue: notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey]?.integerValue ?? 0)!
        var scrollViewOffset: CGFloat = 0
        if directionUp {
            scrollViewOffset = scrollView.contentOffset.y + keyboardHeight
            isScrolled = true
        } else {
            scrollViewOffset =  scrollView.contentOffset.y - keyboardHeight
            isScrolled = false
        }

        scrollViewOffset = max(0, scrollViewOffset)

        UIView.animateWithDuration(animationDuration, delay: 0, options: animationCurve.toOptions(), animations: {
            scrollView.contentOffset.y = scrollViewOffset
            }, completion: nil)
    }

    public func registerViewSlideOnKeyobard(scrollView: UIScrollView) {
        self.scrollView = scrollView
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    public func unregisterViewSlideOnKeyboard() {
        scrollView?.contentOffset = CGPointZero

        scrollView = nil
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }
}