斯威夫特4.1,

使用TPKeyBoardAvoiding类来实现这一点。 这与UIScrollView, UICollectionView, UITableView一起工作很好。

只需将这个类分配给storyboard中的scrollview, collectionview或tableview，或以编程方式创建它的对象。 tpkeyboardavoidscrollview内的所有文本字段或文本视图将在键盘出现和消失时自动调整。

这里是tpkeyboardavoidance的链接

tpkeyboardavoidance for Swift 4.1，

import Foundation
import UIKit

// MARK: - TableView
class TPKeyboardAvoidingTableView:UITableView,UITextFieldDelegate, UITextViewDelegate {

    override var frame:CGRect{
        willSet{
            super.frame = frame
        }

        didSet{
            if hasAutomaticKeyboardAvoidingBehaviour() {return}
            TPKeyboardAvoiding_updateContentInset()
        }
    }

    override var contentSize:CGSize{
        willSet(newValue){
            if hasAutomaticKeyboardAvoidingBehaviour() {
                super.contentSize = newValue
                return
            }

            if newValue.equalTo(self.contentSize)
            {
                return
            }

            super.contentSize = newValue
            self.TPKeyboardAvoiding_updateContentInset()
        }

        //        didSet{
        //            self.TPKeyboardAvoiding_updateContentInset()
        //        }
    }


    override init(frame: CGRect, style: UITableViewStyle) {
        super.init(frame: frame, style: style)
        self.setup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.setup()
    }

    override func awakeFromNib() {
        setup()
    }

    deinit{
        NotificationCenter.default.removeObserver(self)
    }

    func hasAutomaticKeyboardAvoidingBehaviour()->Bool
    {
        if #available(iOS 8.3, *) {
            if self.delegate is UITableViewController
            {
                return true
            }
        }

        return false
    }

    func focusNextTextField()->Bool
    {
        return self.TPKeyboardAvoiding_focusNextTextField()
    }

    @objc func scrollToActiveTextField()
    {
        return self.TPKeyboardAvoiding_scrollToActiveTextField()
    }

    override func willMove(toSuperview newSuperview: UIView?) {
        super.willMove(toSuperview: newSuperview)
        if newSuperview != nil {
            NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)
        }
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.TPKeyboardAvoiding_findFirstResponderBeneathView(self)?.resignFirstResponder()
        super.touchesEnded(touches, with: event)
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if !self.focusNextTextField()
        {
            textField.resignFirstResponder()
        }
        return true
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)

        Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), userInfo: nil, repeats: false)
    }
}

private extension TPKeyboardAvoidingTableView
{
    func setup()
    {
        if self.hasAutomaticKeyboardAvoidingBehaviour() { return }

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillShow(_:)),
                                               name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                               object: nil)

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillHide(_:)),
                                               name: NSNotification.Name.UIKeyboardWillHide,
                                               object: nil)

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

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(scrollToActiveTextField),
                                               name: NSNotification.Name.UITextFieldTextDidBeginEditing,
                                               object: nil)
    }
}

// MARK: - CollectionView
class TPKeyboardAvoidingCollectionView:UICollectionView,UITextViewDelegate {

    override var contentSize:CGSize{
        willSet(newValue){
            if newValue.equalTo(self.contentSize)
            {
                return
            }

            super.contentSize = newValue
            self.TPKeyboardAvoiding_updateContentInset()
        }

        //        didSet{
        //            self.TPKeyboardAvoiding_updateContentInset()
        //        }
    }


    override var frame:CGRect{
        willSet{
            super.frame = frame
        }

        didSet{
            self.TPKeyboardAvoiding_updateContentInset()
        }
    }

    //    override init(frame: CGRect) {
    //        super.init(frame: frame)
    //    }

    override init(frame: CGRect, collectionViewLayout layout: UICollectionViewLayout) {
        super.init(frame: frame, collectionViewLayout: layout)
        setup()
    }

    required init?(coder aDecoder: NSCoder) {
        //        fatalError("init(coder:) has not been implemented")
        super.init(coder: aDecoder)
        self.setup()

    }

    override func awakeFromNib() {
        setup()
    }

    deinit{
        NotificationCenter.default.removeObserver(self)
    }

    func focusNextTextField()->Bool
    {
        return self.TPKeyboardAvoiding_focusNextTextField()
    }

    @objc func scrollToActiveTextField()
    {
        return self.TPKeyboardAvoiding_scrollToActiveTextField()
    }

    override func willMove(toSuperview newSuperview: UIView?) {
        super.willMove(toSuperview: newSuperview)
        if newSuperview != nil {
            NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)
        }
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.TPKeyboardAvoiding_findFirstResponderBeneathView(self)?.resignFirstResponder()
        super.touchesEnded(touches, with: event)
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if !self.focusNextTextField()
        {
            textField.resignFirstResponder()
        }
        return true
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)

        Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), userInfo: nil, repeats: false)
    }
}

private extension TPKeyboardAvoidingCollectionView
{
    func setup()
    {
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillShow(_:)),
                                               name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                               object: nil)

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillHide(_:)),
                                               name: NSNotification.Name.UIKeyboardWillHide,
                                               object: nil)

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

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(scrollToActiveTextField),
                                               name: NSNotification.Name.UITextFieldTextDidBeginEditing,
                                               object: nil)
    }
}

// MARK: - ScrollView
class TPKeyboardAvoidingScrollView:UIScrollView,UITextFieldDelegate,UITextViewDelegate
{
    override var contentSize:CGSize{
        didSet{
            self.TPKeyboardAvoiding_updateFromContentSizeChange()
        }
    }


    override var frame:CGRect{
        didSet{
            self.TPKeyboardAvoiding_updateContentInset()
        }
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.setup()
    }

    override func awakeFromNib() {
        setup()
    }

    func contentSizeToFit()
    {
        self.contentSize = self.TPKeyboardAvoiding_calculatedContentSizeFromSubviewFrames()
    }

    func focusNextTextField() ->Bool
    {
        return self.TPKeyboardAvoiding_focusNextTextField()
    }

    @objc func scrollToActiveTextField()
    {
        return self.TPKeyboardAvoiding_scrollToActiveTextField()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.setup()
    }

    deinit{
        NotificationCenter.default.removeObserver(self)
    }

    override func willMove(toSuperview newSuperview: UIView?) {
        super.willMove(toSuperview: newSuperview)
        if newSuperview != nil {
            NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)
        }
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.TPKeyboardAvoiding_findFirstResponderBeneathView(self)?.resignFirstResponder()
        super.touchesEnded(touches, with: event)
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if !self.focusNextTextField()
        {
            textField.resignFirstResponder()
        }
        return true
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), object: self)

        Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_:)), userInfo: nil, repeats: false)
    }
}

private extension TPKeyboardAvoidingScrollView
{
    func setup()
    {
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillShow(_:)),
                                               name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                               object: nil)

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(TPKeyboardAvoiding_keyboardWillHide(_:)),
                                               name: NSNotification.Name.UIKeyboardWillHide,
                                               object: nil)

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

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(scrollToActiveTextField),
                                               name: NSNotification.Name.UITextFieldTextDidBeginEditing,
                                               object: nil)
    }
}

// MARK: - Process Event
let kCalculatedContentPadding:CGFloat = 10;
let kMinimumScrollOffsetPadding:CGFloat = 20;

extension UIScrollView
{
    @objc func TPKeyboardAvoiding_keyboardWillShow(_ notification:Notification)
    {
        guard let userInfo = notification.userInfo else { return }
        guard let rectNotification = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else
        {
            return
        }

        let keyboardRect = self.convert(rectNotification.cgRectValue , from: nil)
        if keyboardRect.isEmpty
        {
            return
        }

        let state = self.keyboardAvoidingState()

        guard let firstResponder = self.TPKeyboardAvoiding_findFirstResponderBeneathView(self) else { return}
        state.keyboardRect = keyboardRect
        if !state.keyboardVisible
        {
            state.priorInset = self.contentInset
            state.priorScrollIndicatorInsets = self.scrollIndicatorInsets
            state.priorPagingEnabled = self.isPagingEnabled
        }

        state.keyboardVisible = true
        self.isPagingEnabled = false

        if self is TPKeyboardAvoidingScrollView
        {
            state.priorContentSize = self.contentSize
            if self.contentSize.equalTo(CGSize.zero)
            {
                self.contentSize = self.TPKeyboardAvoiding_calculatedContentSizeFromSubviewFrames()
            }
        }

        let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? Float ?? 0.0
        let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? Int ?? 0
        let options = UIViewAnimationOptions(rawValue: UInt(curve))

        UIView.animate(withDuration: TimeInterval(duration),
                       delay: 0,
                       options: options,
                       animations: { [weak self]() -> Void in
                        if let actualSelf = self
                        {
                            actualSelf.contentInset = actualSelf.TPKeyboardAvoiding_contentInsetForKeyboard()
                            let viewableHeight = actualSelf.bounds.size.height - actualSelf.contentInset.top - actualSelf.contentInset.bottom
                            let point = CGPoint(x: actualSelf.contentOffset.x, y: actualSelf.TPKeyboardAvoiding_idealOffsetForView(firstResponder, viewAreaHeight: viewableHeight))
                            actualSelf.setContentOffset(point, animated: false)

                            actualSelf.scrollIndicatorInsets = actualSelf.contentInset
                            actualSelf.layoutIfNeeded()
                        }

        }) { (finished) -> Void in

        }
    }

    @objc func TPKeyboardAvoiding_keyboardWillHide(_ notification:Notification)
    {
        guard let userInfo = notification.userInfo else { return }

        guard let rectNotification = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue else
        {
            return
        }
        let keyboardRect = self.convert(rectNotification.cgRectValue , from: nil)
        if keyboardRect.isEmpty
        {
            return
        }
        let state = self.keyboardAvoidingState()

        if !state.keyboardVisible
        {
            return
        }
        state.keyboardRect = CGRect.zero
        state.keyboardVisible = false

        let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? Float ?? 0.0
        let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? Int ?? 0
        let options = UIViewAnimationOptions(rawValue: UInt(curve))

        UIView.animate(withDuration: TimeInterval(duration),
                       delay: 0,
                       options: options,
                       animations: { [weak self]() -> Void in
                        if let actualSelf = self
                        {
                            if actualSelf is TPKeyboardAvoidingScrollView {
                                actualSelf.contentSize = state.priorContentSize
                                actualSelf.contentInset = state.priorInset
                                actualSelf.scrollIndicatorInsets = state.priorScrollIndicatorInsets
                                actualSelf.isPagingEnabled = state.priorPagingEnabled
                                actualSelf.layoutIfNeeded()
                            }
                        }

        }) { (finished) -> Void in

        }
    }

    func TPKeyboardAvoiding_updateFromContentSizeChange()
    {
        let state = self.keyboardAvoidingState()
        if state.keyboardVisible
        {
            state.priorContentSize = self.contentSize
        }
    }

    func TPKeyboardAvoiding_focusNextTextField() ->Bool
    {
        guard let firstResponder = self.TPKeyboardAvoiding_findFirstResponderBeneathView(self) else { return false}
        guard let view = self.TPKeyboardAvoiding_findNextInputViewAfterView(firstResponder, beneathView: self) else { return false}
        Timer.scheduledTimer(timeInterval: 0.1, target: view, selector: #selector(becomeFirstResponder), userInfo: nil, repeats: false)

        return true

    }

    func TPKeyboardAvoiding_scrollToActiveTextField()
    {
        let state = self.keyboardAvoidingState()

        if !state.keyboardVisible { return }

        let visibleSpace = self.bounds.size.height - self.contentInset.top - self.contentInset.bottom

        let idealOffset = CGPoint(x: 0,
                                  y: self.TPKeyboardAvoiding_idealOffsetForView(self.TPKeyboardAvoiding_findFirstResponderBeneathView(self),
                                                                                viewAreaHeight: visibleSpace))

        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + Double((Int64)(0 * NSEC_PER_SEC)) / Double(NSEC_PER_SEC)) {[weak self] () -> Void in
            self?.setContentOffset(idealOffset, animated: true)
        }
    }

    //Helper
    func TPKeyboardAvoiding_findFirstResponderBeneathView(_ view:UIView) -> UIView?
    {
        for childView in view.subviews
        {
            if childView.responds(to: #selector(getter: isFirstResponder)) && childView.isFirstResponder
            {
                return childView
            }
            let result = TPKeyboardAvoiding_findFirstResponderBeneathView(childView)
            if result != nil
            {
                return result
            }
        }
        return nil
    }

    func TPKeyboardAvoiding_updateContentInset()
    {
        let state = self.keyboardAvoidingState()
        if state.keyboardVisible
        {
            self.contentInset = self.TPKeyboardAvoiding_contentInsetForKeyboard()
        }
    }

    func TPKeyboardAvoiding_calculatedContentSizeFromSubviewFrames() ->CGSize
    {
        let wasShowingVerticalScrollIndicator = self.showsVerticalScrollIndicator
        let wasShowingHorizontalScrollIndicator = self.showsHorizontalScrollIndicator

        self.showsVerticalScrollIndicator = false
        self.showsHorizontalScrollIndicator = false

        var rect = CGRect.zero

        for view in self.subviews
        {
            rect = rect.union(view.frame)
        }

        rect.size.height += kCalculatedContentPadding
        self.showsVerticalScrollIndicator = wasShowingVerticalScrollIndicator
        self.showsHorizontalScrollIndicator = wasShowingHorizontalScrollIndicator

        return rect.size
    }

    func TPKeyboardAvoiding_idealOffsetForView(_ view:UIView?,viewAreaHeight:CGFloat) -> CGFloat
    {
        let contentSize = self.contentSize

        var offset:CGFloat = 0.0
        let subviewRect =  view != nil ? view!.convert(view!.bounds, to: self) : CGRect.zero

        var padding = (viewAreaHeight - subviewRect.height)/2
        if padding < kMinimumScrollOffsetPadding
        {
            padding = kMinimumScrollOffsetPadding
        }

        offset = subviewRect.origin.y - padding - self.contentInset.top

        if offset > (contentSize.height - viewAreaHeight)
        {
            offset = contentSize.height - viewAreaHeight
        }

        if offset < -self.contentInset.top
        {
            offset = -self.contentInset.top
        }

        return offset
    }

    func TPKeyboardAvoiding_contentInsetForKeyboard() -> UIEdgeInsets
    {
        let state = self.keyboardAvoidingState()
        var newInset = self.contentInset;

        let keyboardRect = state.keyboardRect
        newInset.bottom = keyboardRect.size.height - max(keyboardRect.maxY - self.bounds.maxY, 0)

        return newInset

    }

    func TPKeyboardAvoiding_viewIsValidKeyViewCandidate(_ view:UIView)->Bool
    {
        if view.isHidden || !view.isUserInteractionEnabled {return false}

        if view is UITextField
        {
            if (view as! UITextField).isEnabled {return true}
        }

        if view is UITextView
        {
            if (view as! UITextView).isEditable {return true}
        }

        return false
    }

    func TPKeyboardAvoiding_findNextInputViewAfterView(_ priorView:UIView,beneathView view:UIView, candidateView bestCandidate: inout UIView?)
    {
        let priorFrame = self.convert(priorView.frame, to: priorView.superview)
        let candidateFrame = bestCandidate == nil ? CGRect.zero : self.convert(bestCandidate!.frame, to: bestCandidate!.superview)

        var bestCandidateHeuristic = -sqrt(candidateFrame.origin.x*candidateFrame.origin.x + candidateFrame.origin.y*candidateFrame.origin.y) + ( Float(fabs(candidateFrame.minY - priorFrame.minY))<Float.ulpOfOne ? 1e6 : 0)

        for childView in view.subviews
        {
            if TPKeyboardAvoiding_viewIsValidKeyViewCandidate(childView)
            {
                let frame = self.convert(childView.frame, to: view)
                let heuristic = -sqrt(frame.origin.x*frame.origin.x + frame.origin.y*frame.origin.y)
                    + (Float(fabs(frame.minY - priorFrame.minY)) < Float.ulpOfOne ? 1e6 : 0)

                if childView != priorView && (Float(fabs(frame.minY - priorFrame.minY)) < Float.ulpOfOne
                    && frame.minX > priorFrame.minX
                    || frame.minY > priorFrame.minY)
                    && (bestCandidate == nil || heuristic > bestCandidateHeuristic)
                {
                    bestCandidate = childView
                    bestCandidateHeuristic = heuristic
                }
            }else
            {
                self.TPKeyboardAvoiding_findNextInputViewAfterView(priorView, beneathView: view, candidateView: &bestCandidate)
            }
        }
    }

    func TPKeyboardAvoiding_findNextInputViewAfterView(_ priorView:UIView,beneathView view:UIView) ->UIView?
    {
        var candidate:UIView?
        self.TPKeyboardAvoiding_findNextInputViewAfterView(priorView, beneathView: view, candidateView: &candidate)
        return candidate
    }


    @objc func TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(_ obj: AnyObject)
    {
        func processWithView(_ view: UIView) {
            for childView in view.subviews
            {
                if childView is UITextField || childView is UITextView
                {
                    self.TPKeyboardAvoiding_initializeView(childView)
                }else
                {
                    self.TPKeyboardAvoiding_assignTextDelegateForViewsBeneathView(childView)
                }
            }
        }

        if let timer = obj as? Timer, let view = timer.userInfo as? UIView {
            processWithView(view)
        }
        else if let view = obj as? UIView {
            processWithView(view)
        }
    }

    func TPKeyboardAvoiding_initializeView(_ view:UIView)
    {
        if let textField = view as? UITextField,
            let delegate = self as? UITextFieldDelegate, textField.returnKeyType == UIReturnKeyType.default &&
            textField.delegate !== delegate
        {
            textField.delegate = delegate
            let otherView = self.TPKeyboardAvoiding_findNextInputViewAfterView(view, beneathView: self)
            textField.returnKeyType = otherView != nil ? .next : .done

        }
    }

    func keyboardAvoidingState()->TPKeyboardAvoidingState
    {
        var state = objc_getAssociatedObject(self, &AssociatedKeysKeyboard.DescriptiveName) as? TPKeyboardAvoidingState
        if state == nil
        {
            state = TPKeyboardAvoidingState()
            self.state = state
        }

        return self.state!
    }

}

// MARK: - Internal object observer
internal class TPKeyboardAvoidingState:NSObject
{
    var priorInset = UIEdgeInsets.zero
    var priorScrollIndicatorInsets = UIEdgeInsets.zero

    var keyboardVisible = false
    var keyboardRect = CGRect.zero
    var priorContentSize = CGSize.zero

    var priorPagingEnabled = false
}

internal extension UIScrollView
{
    fileprivate struct AssociatedKeysKeyboard {
        static var DescriptiveName = "KeyBoard_DescriptiveName"
    }

    var state:TPKeyboardAvoidingState?{
        get{
            let optionalObject:AnyObject? = objc_getAssociatedObject(self, &AssociatedKeysKeyboard.DescriptiveName) as AnyObject?
            if let object:AnyObject = optionalObject {
                return object as? TPKeyboardAvoidingState
            } else {
                return nil
            }
        }
        set{
            objc_setAssociatedObject(self, &AssociatedKeysKeyboard.DescriptiveName, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
}

最简单的不需要任何代码的方法:

下载KeyboardLayoutConstraint.swift并将文件添加(拖放)到你的项目中，如果你还没有使用Spring动画框架的话。 在你的故事板中，为对象/视图/文本字段创建一个底部约束，选择约束(双击它)并在标识检查器中，将其类从NSLayoutConstraint更改为KeyboardLayoutConstraint。 完成了!

物体会随着键盘同步自动移动。

我已采取以下方式:

当textfield superview为view时，这很有用

class AdminLoginViewController: UIViewController,
UITextFieldDelegate{

    @IBOutlet weak var txtUserName: UITextField!
    @IBOutlet weak var txtUserPassword: UITextField!
    @IBOutlet weak var btnAdminLogin: UIButton!

    private var activeField : UIView?

    var param:String!
    var adminUser : Admin? = nil
    var kbHeight: CGFloat!

    override func viewDidLoad()
    {
        self.addKeyBoardObserver()
        self.addGestureForHideKeyBoard()
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    func addGestureForHideKeyBoard()
    {
        let tapGesture = UITapGestureRecognizer(target: self, action: Selector("hideKeyboard"))
        tapGesture.cancelsTouchesInView = false
        view.addGestureRecognizer(tapGesture)
    }

    func hideKeyboard() {
        self.view.endEditing(true)
    }

    func addKeyBoardObserver(){

        NSNotificationCenter.defaultCenter().addObserver(self, selector: "willChangeKeyboardFrame:",
name:UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "willChangeKeyboardFrame:",
name:UIKeyboardWillHideNotification, object: nil)
    }

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

    //MARK:- textfiled Delegate

    func textFieldShouldBeginEditing(textField: UITextField) -> Bool
    {
         activeField = textField

        return true
    }
    func textFieldShouldEndEditing(textField: UITextField) -> Bool
    {
        if activeField == textField
        {
            activeField = nil
        }

        return true
    }

    func textFieldShouldReturn(textField: UITextField) -> Bool {

        if txtUserName == textField
        {
            txtUserPassword.becomeFirstResponder()
        }
        else if (textField == txtUserPassword)
        {
            self.btnAdminLoginAction(nil)
        }
        return true;
    }

    func willChangeKeyboardFrame(aNotification : NSNotification)
    {
       if self.activeField != nil && self.activeField!.isFirstResponder()
    {
        if let keyboardSize =  (aNotification.userInfo![UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
        {
            let dy = (self.activeField?.superview?.convertRect((self.activeField?.frame)!, toView: view).origin.y)!

            let height = (self.view.frame.size.height - keyboardSize.size.height)

            if dy > height
            {
                var frame = self.view.frame

                frame.origin.y = -((dy - height) + (self.activeField?.frame.size.height)! + 20)

                self.view.frame = frame
            }
        }
    }
    else
    {
        var frame = self.view.frame
        frame.origin.y = 0
        self.view.frame = frame
    }
    } }

另一个解决方案，不依赖于自动布局，约束或任何出口。您所需要的是滚动视图中的字段。

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
}

func makeSpaceForKeyboard(notification: NSNotification) {
    let info = notification.userInfo!
    let keyboardHeight:CGFloat = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().size.height
    let duration:Double = info[UIKeyboardAnimationDurationUserInfoKey] as! Double

    if notification.name == UIKeyboardWillShowNotification {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            var frame = self.view.frame
            frame.size.height = frame.size.height - keyboardHeight
            self.view.frame = frame
        })
    } else {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            var frame = self.view.frame
            frame.size.height = frame.size.height + keyboardHeight
            self.view.frame = frame
        })
    }

}

对于任何不使用故事板设置布局约束的人。这是一种纯粹的编程方式，让它在Swift 5上工作:

在viewController中定义一个空约束。在这种情况下，我正在构建一个聊天应用程序，在屏幕的最底部有一个包含文本视图的UIView。

var discussionsMessageBoxBottomAnchor: NSLayoutConstraint = NSLayoutConstraint()

在viewDidLoad中为最底部的视图添加约束。在本例中是discussionsMessageBox。另外，为键盘事件添加监听器。

为了正确地初始化约束，您需要首先添加子视图，然后定义约束。

NotificationCenter.default.addObserver(self,
                                       selector: #selector(self.keyboardNotification(notification:)),
                                       name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                       object: nil)

view.addSubview(discussionsMessageBox)

if #available(iOS 11.0, *) {
    discussionsMessageBoxBottomAnchor = discussionsMessageBox.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0)
} else {
    // Fallback on earlier versions
    discussionsMessageBoxBottomAnchor = discussionsMessageBox.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0)
}

NSLayoutConstraint.activate([ discussionsMessageBoxBottomAnchor ])

定义deinit。

deinit {
        NotificationCenter.default.removeObserver(self)
    }

接下来添加@JosephLord定义的代码，并对偏移量进行修正。

extension DiscussionsViewController {
    @objc func keyboardNotification(notification: NSNotification) {
        guard let userInfo = notification.userInfo else { return }
        
        let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
        let endFrameY = endFrame?.origin.y ?? 0
        let duration:TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
        let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
        let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
        let animationCurve:UIView.AnimationOptions = UIView.AnimationOptions(rawValue: animationCurveRaw)
        
        if endFrameY >= UIScreen.main.bounds.size.height {
            self.discussionsMessageBoxBottomAnchor.constant = 0.0
        } else {
            //Changed line
            self.discussionsMessageBoxBottomAnchor.constant = -1 * (endFrame?.size.height ?? 0.0)
        }
        
        UIView.animate(
            withDuration: duration,
            delay: TimeInterval(0),
            options: animationCurve,
            animations: { self.view.layoutIfNeeded() },
            completion: nil)
    }
}

如果你正在使用自动布局，我假设你已经设置了底部空间为Superview约束。如果是这种情况，您只需更新约束的值。这是你如何用一点动画来做到这一点。

func keyboardWasShown(notification: NSNotification) {
    let info = notification.userInfo!
    let keyboardFrame: CGRect = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()

    UIView.animateWithDuration(0.1, animations: { () -> Void in
        self.bottomConstraint.constant = keyboardFrame.size.height + 20
    })
}

添加硬编码的20只是为了将文本框弹出到键盘上方一点。否则键盘的上边距和文本框的下边距将会接触。

当键盘关闭时，将约束的值重置为原始值。