我对初学者的两点建议: 在上面的例子中，有人改变坐标，其他人使用“自动调整蒙版”和其他约束:

正如苹果所说，不要将这三种逻辑混合在一起。 如果你在故事板中有约束，不要尝试改变x/y。这绝对行不通。

 override func viewWillAppear(animated: Bool)
 {
 super.viewWillAppear(animated)

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

 }

 // MARK: - keyboard
 func keyboardWillShow(notification: NSNotification) 
{

if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: keyboardSize.height, right:contentInsets.right)
                    // ...
                } else {
                    // no UIKeyboardFrameBeginUserInfoKey entry in userInfo
                }
            } else {
                // no userInfo dictionary in notification
            }
        }

func keyboardWillHide(notification: NSNotification) 
{
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: 0, right:contentInsets.right)
 }

我需要在swift 4中移动一个UIView，当键盘打开和关闭。所有的答案都帮不了我。因为打开表情包时键盘高度会发生变化。所以我的代码是:

@objc func keyboardWillShow(sender: NSNotification) {

    if let keyboardFrame: NSValue = sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {

        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height

        if(self.oldHeight == keyboardHeight){
            self.sendingView.frame.origin.y -= keyboardHeight
            self.oldHeight = keyboardHeight
        }
        else{
            self.sendingView.frame.origin.y += self.oldHeight
            self.sendingView.frame.origin.y -= keyboardHeight
            self.oldHeight = keyboardHeight
        }
    }
}

@objc func keyboardWillHide(sender: NSNotification) {

    if let keyboardFrame: NSValue = sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {

        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height

        self.sendingView.frame.origin.y += keyboardHeight

    }
}

和在viewDidLoad():

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

自我。oldHeight = CGFloat()并定义为类顶部的字段。

这个视频教程是最好的。7分钟长，会很有意义。这样一个简单的解决方案，当你有多个文本字段，并希望滚动视图移动“x”数量的像素时，特定的文本字段被点击。

https://youtu.be/VuiPGJOEBH4

就这些步骤:

-把你所有的文本字段放在一个滚动视图中，约束到视图的边缘。

-连接所有的文本字段和滚动视图作为视图控制器的委托。

-用IBOutlet连接所有文本字段和滚动视图。

class ViewController: UIViewController, UITextFieldDelegate {

添加UITextFieldDelegate协议到你的类中

@IBOutlet var stateAddress: UITextField!
@IBOutlet var zipAddress: UITextField!
@IBOutlet var phoneNumber: UITextField!
@IBOutlet var vetEmailAddress: UITextField!    
@IBOutlet weak var scrollView: UIScrollView!

-在swift文件中添加UITextFieldDelegate方法:

func textFieldShouldReturn(textField: UITextField) -> Bool {

    textField.resignFirstResponder()
    return true
}


func textFieldDidBeginEditing(textField: UITextField) {

    if (textField == self.stateAddress) {
        scrollView.setContentOffset(CGPointMake(0, 25), animated: true)
    }
    else if (textField == self.zipAddress) {
        scrollView.setContentOffset(CGPointMake(0, 57), animated: true)
    }
    else if (textField == self.phoneNumber) {
        scrollView.setContentOffset(CGPointMake(0, 112), animated: true)
    }
    else if (textField == self.vetEmailAddress) {
        scrollView.setContentOffset(CGPointMake(0, 142), animated: true)
    }
}

func textFieldDidEndEditing(textField: UITextField) {

    scrollView.setContentOffset(CGPointMake(0, 0), animated: true)
}

第一种方法只是激活键盘上的返回按钮来关闭键盘。第二个是当你点击到任何特定的文本域，然后设置你的滚动视图滚动的距离的y偏移(我的是基于我的视图控制器上的y位置25,57,112,142)。最后一个说，当你从键盘上点击时，滚动视图会回到原来的位置。

我使我的视图像素完美的这种方式!

将这个添加到你的视图控制器中。效果非常好。只是调整数值。

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

@objc func keyboardWillShow(sender: NSNotification) {
    self.view.frame.origin.y -= 150
}
@objc func keyboardWillHide(sender: NSNotification) {
    self.view.frame.origin.y += 150
}

我做了一个椰子荚来简化问题:

https://github.com/xtrinch/KeyboardLayoutHelper

如何使用:

做一个自动布局底部约束，在模块KeyboardLayoutHelper中给它一个KeyboardLayoutConstraint类，pod将做必要的工作来增加它，以适应出现和消失的键盘。关于如何使用它(我做了两个:一个scrollView内的textFields，和垂直居中的textFields与两个基本视图-登录和注册)的例子项目。

底部布局约束可以是容器视图，textField本身，任何你能想到的。