Swift 3解决方案，使用UITextField的有序数组

func nextTextField() {
    let textFields = // Your textfields array

    for i in 0 ..< textFields.count{
        if let textfield = textFields[i], textfield.isFirstResponder{
            textfield.resignFirstResponder()
            if i+1 < textFields.count, let nextextfield = textFields[i+1]{
                nextextfield.becomeFirstResponder()
                return
            }
        }
    }
}

没有usings标签，也没有为nextField/nextTextField添加属性，你可以尝试模拟TAB，其中"testInput"是你当前的活动字段:

if ([textInput isFirstResponder])
    [textInput.superview.subviews enumerateObjectsAtIndexes:
     [NSIndexSet indexSetWithIndexesInRange:
      NSMakeRange([textInput.superview.subviews indexOfObject:textInput]+1,
                  [textInput.superview.subviews count]-[textInput.superview.subviews indexOfObject:textInput]-1)]
                                                    options:0 usingBlock:^(UIView *obj, NSUInteger idx, BOOL *stop) {
                                                        *stop = !obj.hidden && [obj becomeFirstResponder];
                                                    }];
if ([textInput isFirstResponder])
    [textInput.superview.subviews enumerateObjectsAtIndexes:
     [NSIndexSet indexSetWithIndexesInRange:
      NSMakeRange(0,
                  [textInput.superview.subviews indexOfObject:textInput])]
                                                    options:0 usingBlock:^(UIView *obj, NSUInteger idx, BOOL *stop) {
                                                        *stop = !obj.hidden && [obj becomeFirstResponder];
                                                    }];

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)。

我用Michael G. Emmons的答案已经有一年了，效果很好。我最近注意到，立即调用resignFirstResponder，然后立即调用becomeFirstResponder会导致键盘“故障”，消失，然后立即出现。我稍微改变了他的版本，跳过resignFirstResponder如果nextField是可用的。

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{ 

    if ([textField isKindOfClass:[NRTextField class]])
    {
        NRTextField *nText = (NRTextField*)textField;
        if ([nText nextField] != nil){
            dispatch_async(dispatch_get_main_queue(),
                           ^ { [[nText nextField] becomeFirstResponder]; });

        }
        else{
            [textField resignFirstResponder];
        }
    }
    else{
        [textField resignFirstResponder];
    }

    return true;

}

解决方案在Swift 3.1，连接你的文本字段IBOutlets设置你的文本字段委托在viewDidLoad，然后在textFieldShouldReturn导航你的动作

class YourViewController: UIViewController,UITextFieldDelegate {

        @IBOutlet weak var passwordTextField: UITextField!
        @IBOutlet weak var phoneTextField: UITextField!

        override func viewDidLoad() {
            super.viewDidLoad()
            self.passwordTextField.delegate = self
            self.phoneTextField.delegate = self
            // Set your return type
            self.phoneTextField.returnKeyType = .next
            self.passwordTextField.returnKeyType = .done
        }

        func textFieldShouldReturn(_ textField: UITextField) -> Bool{
            if textField == self.phoneTextField {
                self.passwordTextField.becomeFirstResponder()
            }else if textField == self.passwordTextField{
                // Call login api
                self.login()
            }
            return true
        }

    }