下面是一个在UIControl上使用类别的选项卡实现。这个解决方案具有Michael和Anth0方法的所有优点，但适用于所有uicontrol，而不仅仅是UITextFields。它还可以与接口生成器和故事板无缝工作。

源代码和示例应用程序:UIControlsWithTabbing的GitHub仓库

用法:

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField transferFirstResponderToNextControl];
    return NO;
}

标题:

//
// UIControl+NextControl.h
// UIControlsWithTabbing
//

#import <UIKit/UIKit.h>

@interface UIControl (NextControl)

@property (nonatomic, weak) IBOutlet UIControl *nextControl;

- (BOOL)transferFirstResponderToNextControl;

@end

实现:

#import "UIControl+NextControl.h"
#import <objc/runtime.h>

static char defaultHashKey;

@implementation UIControl (NextControl)

- (UIControl *)nextControl
{
    return objc_getAssociatedObject(self, &defaultHashKey);
}

- (void)setNextControl:(UIControl *)nextControl
{
    objc_setAssociatedObject(self, &defaultHashKey, nextControl, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (BOOL)transferFirstResponderToNextControl
{
    if (self.nextControl)
    {
        [self.nextControl becomeFirstResponder];

        return YES;
    }

    [self resignFirstResponder];

    return NO;
}

@end

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
        }

    }

我喜欢Anth0和Answerbot已经提出的面向对象解决方案。然而，我正在开发一个快速而小型的POC，所以我不想让子类和类别使事情变得混乱。

另一个简单的解决方案是创建一个字段的NSArray，并在按下next时查找下一个字段。不是面向对象的解决方案，而是快速、简单且易于实现。此外，您可以一目了然地查看和修改排序。

下面是我的代码(基于这个线程中的其他答案):

@property (nonatomic) NSArray *fieldArray;

- (void)viewDidLoad {
    [super viewDidLoad];

    fieldArray = [NSArray arrayWithObjects: firstField, secondField, thirdField, nil];
}

- (BOOL) textFieldShouldReturn:(UITextField *) textField {
    BOOL didResign = [textField resignFirstResponder];
    if (!didResign) return NO;

    NSUInteger index = [self.fieldArray indexOfObject:textField];
    if (index == NSNotFound || index + 1 == fieldArray.count) return NO;

    id nextField = [fieldArray objectAtIndex:index + 1];
    activeField = nextField;
    [nextField becomeFirstResponder];

    return NO;
}

I always return NO because I don't want a line break inserted. Just thought I'd point that out since when I returned YES it would automatically exit the subsequent fields or insert a line break in my TextView. It took me a bit of time to figure that out. activeField keeps track of the active field in case scrolling is necessary to unobscure the field from the keyboard. If you have similar code, make sure you assign the activeField before changing the first responder. Changing first responder is immediate and will fire the KeyboardWasShown event immediately.

下面是一个在UIControl上使用类别的选项卡实现。这个解决方案具有Michael和Anth0方法的所有优点，但适用于所有uicontrol，而不仅仅是UITextFields。它还可以与接口生成器和故事板无缝工作。

源代码和示例应用程序:UIControlsWithTabbing的GitHub仓库

用法:

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField transferFirstResponderToNextControl];
    return NO;
}

标题:

//
// UIControl+NextControl.h
// UIControlsWithTabbing
//

#import <UIKit/UIKit.h>

@interface UIControl (NextControl)

@property (nonatomic, weak) IBOutlet UIControl *nextControl;

- (BOOL)transferFirstResponderToNextControl;

@end

实现:

#import "UIControl+NextControl.h"
#import <objc/runtime.h>

static char defaultHashKey;

@implementation UIControl (NextControl)

- (UIControl *)nextControl
{
    return objc_getAssociatedObject(self, &defaultHashKey);
}

- (void)setNextControl:(UIControl *)nextControl
{
    objc_setAssociatedObject(self, &defaultHashKey, nextControl, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (BOOL)transferFirstResponderToNextControl
{
    if (self.nextControl)
    {
        [self.nextControl becomeFirstResponder];

        return YES;
    }

    [self resignFirstResponder];

    return NO;
}

@end

一个快速扩展，应用mxcl的答案，使这特别容易(适应swift 2.3由旅行者):

extension UITextField {
    class func connectFields(fields:[UITextField]) -> Void {
        guard let last = fields.last else {
            return
        }
        for i in 0 ..< fields.count - 1 {
            fields[i].returnKeyType = .Next
            fields[i].addTarget(fields[i+1], action: "becomeFirstResponder", forControlEvents: .EditingDidEndOnExit)
        }
        last.returnKeyType = .Done
        last.addTarget(last, action: #selector(UIResponder.resignFirstResponder), forControlEvents: .EditingDidEndOnExit)
    }
}

它很容易使用:

UITextField.connectFields([field1, field2, field3])

扩展将设置返回按钮为“下一步”为所有但最后一个字段和“完成”为最后一个字段，并转移焦点/解散键盘时，这些被轻敲。

Swift < 2.3

extension UITextField {
    class func connectFields(fields:[UITextField]) -> Void {
        guard let last = fields.last else {
            return
        }
        for var i = 0; i < fields.count - 1; i += 1 {
            fields[i].returnKeyType = .Next
            fields[i].addTarget(fields[i+1], action: "becomeFirstResponder", forControlEvents: .EditingDidEndOnExit)
        }
        last.returnKeyType = .Done
        last.addTarget(last, action: "resignFirstResponder", forControlEvents: .EditingDidEndOnExit)
    }
}

斯威夫特3: 像这样使用-

UITextField.connectFields(fields: [field1, field2])

Extension:
    extension UITextField {
        class func connectFields(fields:[UITextField]) -> Void {
            guard let last = fields.last else {
                return
            }
            for i in 0 ..< fields.count - 1 {
                fields[i].returnKeyType = .next
                fields[i].addTarget(fields[i+1], action: #selector(UIResponder.becomeFirstResponder), for: .editingDidEndOnExit)
            }
            last.returnKeyType = .go
            last.addTarget(last, action: #selector(UIResponder.resignFirstResponder), for: .editingDidEndOnExit)
        }
    }

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.