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;

}

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
            }
        }
    }
}

退出一个文本字段后，调用[otherTextField becomeFirstResponder]，下一个字段获得焦点。

这实际上是一个棘手的问题，因为通常你还想滚动屏幕或以其他方式调整文本字段的位置，以便在编辑时容易看到。只要确保做大量的测试，以不同的方式进入和退出文本字段，并提前离开(总是给用户一个选项，取消键盘，而不是进入下一个字段，通常在导航栏中有“完成”)

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.

我在我的故事板中有大约10+ UITextField，我启用下一个功能的方式是通过创建一个UITextField数组，并使下一个UITextField成为firstResponder。下面是实现文件:

#import "RegistrationTableViewController.h"

@interface RegistrationTableViewController ()
@property (weak, nonatomic) IBOutlet UITextField *fullNameTextField;
@property (weak, nonatomic) IBOutlet UITextField *addressTextField;
@property (weak, nonatomic) IBOutlet UITextField *address2TextField;
@property (weak, nonatomic) IBOutlet UITextField *cityTextField;
@property (weak, nonatomic) IBOutlet UITextField *zipCodeTextField;
@property (weak, nonatomic) IBOutlet UITextField *urlTextField;
@property (weak, nonatomic) IBOutlet UITextField *usernameTextField;
@property (weak, nonatomic) IBOutlet UITextField *emailTextField;
@property (weak, nonatomic) IBOutlet UITextField *passwordTextField;
@property (weak, nonatomic) IBOutlet UITextField *confirmPWTextField;

@end
NSArray *uiTextFieldArray;
@implementation RegistrationTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    NSLog(@"view did load");
    uiTextFieldArray = @[self.fullNameTextField,self.addressTextField,self.address2TextField,self.cityTextField,self.zipCodeTextField,self.urlTextField,self.usernameTextField,self.emailTextField,self.passwordTextField,self.confirmPWTextField];
    for(UITextField *myField in uiTextFieldArray){
        myField.delegate = self;
    }


}
-(BOOL)textFieldShouldReturn:(UITextField *)textField{
    long index = [uiTextFieldArray indexOfObject:textField];
    NSLog(@"%ld",index);
    if(index < (uiTextFieldArray.count - 1)){
        [uiTextFieldArray[++index] becomeFirstResponder];
    }else{
        [uiTextFieldArray[index] resignFirstResponder];
    }
    return YES;
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end