下面是一个swift3版本的Anth0的答案。我把它贴在这里，以帮助任何想要利用他的伟大答案的敏捷开发人员!当您设置关联对象时，我擅自添加了一个返回键类型“Next”。

extension UITextField {

  @nonobjc static var NextHashKey: UniChar = 0

  var nextTextField: UITextField? {
    get {
      return objc_getAssociatedObject(self, 
        &UITextField.NextHashKey) as? UITextField
    }
    set(next) {
     self.returnKeyType = UIReturnKeyType.next
     objc_setAssociatedObject(self,
      &UITextField.NextHashKey,next,.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
  }
}

下面是另一个扩展，它显示了使用上述代码循环遍历UITextFields列表的可能性。

extension UIViewController: UITextFieldDelegate {
 public func textFieldShouldReturn(_ textField: UITextField) -> Bool {
   guard let next = textField.nextTextField else {
     textField.resignFirstResponder()
     return true
   }

    next.becomeFirstResponder()
    return false
  }
}

然后在你的ViewController或者其他地方，你可以像这样设置你的文本框。

@IBOutlet fileprivate weak var textfield1: UITextField!
@IBOutlet fileprivate weak var textfield2: UITextField!
@IBOutlet fileprivate weak var textfield3: UITextField!

...

[textfield1, textfield2, textfield3].forEach{ $0?.delegate = self }

textfield1.nextTextField = textfield2
textfield2.nextTextField = textfield3
// We don't assign a nextTextField to textfield3 because we want 
// textfield3 to be the last one and resignFirstResponder when 
// the return button on the soft keyboard is tapped.

下面是一个没有授权的例子:

tf1.addTarget(tf2, action: #selector(becomeFirstResponder), for: .editingDidEndOnExit)
tf2.addTarget(tf3, action: #selector(becomeFirstResponder), for: .editingDidEndOnExit)

ObjC:

[tf1 addTarget:tf2 action:@selector(becomeFirstResponder) forControlEvents:UIControlEventEditingDidEndOnExit];
[tf2 addTarget:tf3 action:@selector(becomeFirstResponder) forControlEvents:UIControlEventEditingDidEndOnExit];

使用UIControlEventEditingDidEndOnExit UITextField动作工作(大部分是未知的)。

您还可以很容易地将其连接到故事板中，因此不需要委托或代码。

编辑:实际上我不知道如何在故事板中连接这个。becomeFirstResponder似乎不是这个control-event的一个提供的动作，这是一个遗憾。尽管如此，你可以将所有的文本字段连接到你的ViewController中的一个动作，然后决定哪个textField成为基于发送者的firstresponder(虽然它不像上面的编程解决方案那么优雅，所以IMO用viewDidLoad中的上述代码来做)。

如果有人想这样。我认为这是最接近问题所要求的要求

下面是我如何实现它

为需要设置的每个文本字段添加附件视图，使用

func setAccessoryViewFor(textField : UITextField)    {
    let toolBar = UIToolbar()
    toolBar.barStyle = .default
    toolBar.isTranslucent = true
    toolBar.sizeToFit()

    // Adds the buttons

    // Add previousButton
    let prevButton = UIBarButtonItem(title: "<", style: .plain, target: self, action: #selector(previousPressed(sender:)))
    prevButton.tag = textField.tag
    if getPreviousResponderFor(tag: textField.tag) == nil {
        prevButton.isEnabled = false
    }

    // Add nextButton
    let nextButton = UIBarButtonItem(title: ">", style: .plain, target: self, action: #selector(nextPressed(sender:)))
    nextButton.tag = textField.tag
    if getNextResponderFor(tag: textField.tag) == nil {
        nextButton.title = "Done"
    }

    let spaceButton = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
    toolBar.setItems([prevButton,spaceButton,nextButton], animated: false)
    toolBar.isUserInteractionEnabled = true
    textField.inputAccessoryView = toolBar
}

使用以下函数来处理轻拍

func nextPressed(sender : UIBarButtonItem) {
    if let nextResponder = getNextResponderFor(tag: sender.tag) {
        nextResponder.becomeFirstResponder()
    } else {
        self.view.endEditing(true)
    }

}

func previousPressed(sender : UIBarButtonItem) {
    if let previousResponder = getPreviousResponderFor(tag : sender.tag)  {
        previousResponder.becomeFirstResponder()
    }
}

func getNextResponderFor(tag : Int) -> UITextField? {
    return self.view.viewWithTag(tag + 1) as? UITextField
}

func getPreviousResponderFor(tag : Int) -> UITextField? {
    return self.view.viewWithTag(tag - 1) as? UITextField
}

您需要按您希望下一个/前一按钮响应的顺序给出textFields标记。

我尝试使用一种更复杂的方法来解决这个问题，该方法基于为UITableView中的每个单元格(或UITextField)分配一个稍后可以检索的唯一标签值: activate-next-uitextfield-in-uitableview-ios

我希望这能有所帮助!

一个更加一致和健壮的方法是使用NextResponderTextField 你可以完全从接口构建器中配置它，而不需要设置委托或使用view.tag。

你所需要做的就是

将UITextField的类类型设置为NextResponderTextField 然后设置nextResponderField的出口指向下一个responder它可以是任何UITextField或任何UIResponder子类。它也可以是一个UIButton，库足够智能，只有当它被启用时才会触发按钮的TouchUpInside事件。

下面是运行中的库:

我已经实现了在视图层次结构中通过Responders导航的动态解决方案。其思想是，在整个层次结构中搜索下一个可能的响应器，根据需要向前或向后搜索。

UIView搜索扩展:

UIView+Cat.h

- (UIResponder *)getNextFirstResponder;
- (UIResponder *)getPreviousFirstResponder;

UIView+Cat.m

- (UIResponder *)getPreviousFirstResponder {
    if (!self.superview) {
        return nil;
    }
    
    BOOL hasreachedself = NO;
    for (NSInteger i = self.superview.subviews.count-1; i >= 0; i--) {
        UIView *v = [self.superview.subviews objectAtIndex:i];
        if (v == self) {
            hasreachedself = YES;
            continue;
        }
        if (!hasreachedself) continue;
        
        if ([v canBecomeFirstResponder] && !v.hidden) {
            return v;
        }
        UIResponder *subResponder = [self getNextFirstResponderInView:v];
        if (subResponder) {
            return subResponder;
        }
    }
    
    //search hierachicaly in superviews
    return [self.superview getPreviousFirstResponder];
}

- (UIResponder *)getNextFirstResponder {
    if (!self.superview) {
        return nil;
    }
    
    BOOL hasreachedself = NO;
    for (UIView *v in self.superview.subviews) {
        if (v == self) {
            hasreachedself = YES;
            continue;
        }
        if (!hasreachedself) continue;
        
        if ([v canBecomeFirstResponder] && !v.hidden) {
            return v;
        }
        UIResponder *subResponder = [self getNextFirstResponderInView:v];
        if (subResponder) {
            return subResponder;
        }
    }
    
    //search hierachicaly in superviews
    return [self.superview getNextFirstResponder];
}

- (UIResponder *)getNextFirstResponderInView:(UIView *)view {
    if ([view canBecomeFirstResponder] && !view.hidden) {
        return view;
    }
    for (UIView *v in view.subviews) {
        UIResponder *subResponder = [self getNextFirstResponderInView:v];
        if (subResponder) {
            return subResponder;
        }
    }
    return nil;
}

用法:添加UIToolbar到UITextField / UITextView(在类别或子类中):

- (void)addToolbarInputAccessoryView {
    UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:CGRectZero];
    UIBarButtonItem *prev = [[UIBarButtonItem alloc] initWithImage:[UIImage systemImageNamed:@"chevron.up"] style:UIBarButtonItemStylePlain target:self action:@selector(moveToPreviousFirstResponder)];
    UIBarButtonItem *next = [[UIBarButtonItem alloc] initWithImage:[UIImage systemImageNamed:@"chevron.down"] style:UIBarButtonItemStylePlain target:self action:@selector(moveToNextFirstResponder)];
    UIBarButtonItem *space = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    UIBarButtonItem *done = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(hideKeyboard)];
    toolbar.items = @[prev, next, space, done];
    
    if ([[UITextField appearance] keyboardAppearance] == UIKeyboardAppearanceDark) {
        toolbar.barStyle = UIBarStyleBlack;
        toolbar.translucent = YES;
        [toolbar setBarTintColor:[UIColor blackColor]];
        [toolbar setTintColor:[UIColor whiteColor]];
    }
    
    [toolbar sizeToFit];
    
    self.inputAccessoryView = toolbar;
}

- (void)hideKeyboard {
    [self resignFirstResponder];
}

- (void)moveToNextFirstResponder {
    UIResponder *next = [self getNextFirstResponder];
    if (next) {
        [next becomeFirstResponder];
    }
    else {
        [self resignFirstResponder];
    }
}

- (void)moveToPreviousFirstResponder {
    UIResponder *prev = [self getPreviousFirstResponder];
    if (prev) {
        [prev becomeFirstResponder];
    }
    else {
        [self resignFirstResponder];
    }
}