这是我使用自动布局的版本：

其想法是将包含文本字段/文本视图的视图嵌入UIScrollView中，从底部到其超级视图设置一个约束，创建一个出口，并使用通知根据键盘高度更新其常量。这是基于此处的Apple示例，以及此处使用AutoLayout的UIScrollView上的Apple技术说明。

1） 将视图V嵌入UIScrollView S：如果已经设置了常量和子视图，则可以在ViewController的视图中复制/粘贴视图和子视图；然后使用编辑器->嵌入菜单嵌入视图，最后删除复制的视图。）

2） 设置以下约束：

S到顶部布局指南：0S至底部布局指南：0通向超级视图的S：0S尾随到超级视图：0V顶部空间到超级视图：0V底部空间到超级视图：0超级视图的V尾随空格：0超视图的V前导空格：0V等于S的宽度最新底部V子视图到超级视图：20

3） 从视图控制器的最新约束创建出口

4） 使用以下代码：

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *bottomSpaceToContentView;

// ...

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    // ...

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Handle keyboard

// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    self.bottomSpaceToContentView.constant = kBottomMargin + kbSize.height;
    [self.view layoutIfNeeded];
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    self.bottomSpaceToContentView.constant = kBottomMargin;
    [self.view layoutIfNeeded];
}

哈哈，它起作用了！

这是我的“仅UITextView扩展”解决方案，基于Paul Hudson@twostraws的解决方案（向他和这里所有类似答案的作者致敬）。

import UIKit

extension UITextView {
    
    func adjustableForKeyboard() {
        let notificationCenter = NotificationCenter.default
        
        notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillHideNotification, object: nil)
        notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }
    
    @objc private func adjustForKeyboard(notification: Notification) {
        guard let keyboardValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
            return
        }

        let keyboardScreenEndFrame = keyboardValue.cgRectValue
        let keyboardViewEndFrame = convert(keyboardScreenEndFrame, from: window)
        
        if notification.name == UIResponder.keyboardWillHideNotification {
            contentInset = .zero
        } else {
            contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardViewEndFrame.height - safeAreaInsets.bottom, right: 0)
        }

        scrollIndicatorInsets = contentInset
        scrollRangeToVisible(selectedRange)
    }
}

用法：

override func viewDidLoad() {
    super.viewDidLoad()
    
    textView.adjustableForKeyboard()
}

您不需要为一个简单的任务编写这么多代码。有一个名为“IQKeyboardManager”的CocoaPod将为您完成任务：

pod 'IQKeyboardManager'

然后在从didFinishLaunchingWithOptions返回之前，在AppDelegate中使用以下代码：

IQKeyboardManager.shared().isEnabled = true
IQKeyboardManager.shared().shouldResignOnTouchOutside = true
IQKeyboardManager.shared().isEnableAutoToolbar = false

如果您现在的内容不适合iPhone屏幕，您只需要一个ScrollView。（如果您添加ScrollView作为组件的超级视图，只是为了在键盘启动时使TextField向上滚动，那么就不需要了。）防止TextFields被键盘覆盖的标准方法是在显示键盘时向上/向下移动视图。

下面是一些示例代码：

#define kOFFSET_FOR_KEYBOARD 80.0

-(void)keyboardWillShow {
    // Animate the current view out of the way
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)keyboardWillHide {
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:mailTf])
    {
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
        {
            [self setViewMovedUp:YES];
        }
    }
}

//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3]; // if you want to slide up the view

    CGRect rect = self.view.frame;
    if (movedUp)
    {
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard 
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    }
    else
    {
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

需要考虑的一件事是，您是否希望单独使用UITextField。我还没有遇到任何设计良好的iPhone应用程序在UITableViewCells之外实际使用UITextFields。

这将是一些额外的工作，但我建议您实现表视图中的所有数据条目视图。将UITextView添加到UITableViewCells。

如果文本字段应该位于屏幕底部，那么最神奇的解决方案是在视图控制器上覆盖以下内容：

override var inputAccessoryView: UIView? {
    return <yourTextField>
}