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:

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
        }

    }

我很惊讶，这里有这么多答案没有理解一个简单的概念:在应用程序中的控件中导航不是视图本身应该做的事情。控制器的工作是决定将哪个控件作为下一个第一响应器。

此外，大多数答案只适用于前进导航，但用户也可能想后退。

这就是我想到的。表单应该由视图控制器管理，视图控制器是响应器链的一部分。所以你可以完全自由地实现以下方法:

#pragma mark - Key Commands

- (NSArray *)keyCommands
{
    static NSArray *commands;

    static dispatch_once_t once;
    dispatch_once(&once, ^{
        UIKeyCommand *const forward = [UIKeyCommand keyCommandWithInput:@"\t" modifierFlags:0 action:@selector(tabForward:)];
        UIKeyCommand *const backward = [UIKeyCommand keyCommandWithInput:@"\t" modifierFlags:UIKeyModifierShift action:@selector(tabBackward:)];

        commands = @[forward, backward];
    });

    return commands;
}

- (void)tabForward:(UIKeyCommand *)command
{
    NSArray *const controls = self.controls;
    UIResponder *firstResponder = nil;

    for (UIResponder *const responder in controls) {
        if (firstResponder != nil && responder.canBecomeFirstResponder) {
            [responder becomeFirstResponder]; return;
        }
        else if (responder.isFirstResponder) {
            firstResponder = responder;
        }
    }

    [controls.firstObject becomeFirstResponder];
}

- (void)tabBackward:(UIKeyCommand *)command
{
    NSArray *const controls = self.controls;
    UIResponder *firstResponder = nil;

    for (UIResponder *const responder in controls.reverseObjectEnumerator) {
        if (firstResponder != nil && responder.canBecomeFirstResponder) {
            [responder becomeFirstResponder]; return;
        }
        else if (responder.isFirstResponder) {
            firstResponder = responder;
        }
    }

    [controls.lastObject becomeFirstResponder];
}

额外的逻辑滚动屏幕外的响应可见之前可能适用。

这种方法的另一个优点是，您不需要子类化您可能想要显示的所有类型的控件(如UITextFields)，而是可以在控制器级别管理逻辑，老实说，在控制器级别管理逻辑是正确的。

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

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];
    }
}