How to navigate through textfields (Next / Done Buttons)

A very easy method for dismissing the keyboard when the 'Done' button is pressed is:

Create a new IBAction in the header

- (IBAction)textFieldDoneEditing:(id)sender;

In the implementation file (.m file) add the following method:

- (IBAction)textFieldDoneEditing:(id)sender 
{ 
  [sender resignFirstResponder];
}

Then, when you come to link the IBAction to the textfield - link to the 'Did End On Exit' event.

First set keyboard return key in xib, otherwise you can write code in viewdidload:

passWord.returnKeyType = UIReturnKeyNext;

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    if(textField == eMail) {
        [textField resignFirstResponder];
        [userName becomeFirstResponder];
    }
    if (textField==userName) {
        [textField resignFirstResponder];
        [passWord becomeFirstResponder];
    }
    if (textField==passWord) {
        [textField resignFirstResponder];
        [country becomeFirstResponder];
    }
    if (textField==country) {
        [textField resignFirstResponder];
    }
    return YES;
}

A safer and more direct way, assuming:

• the text field delegates are set to your view controller
• all of the text fields are subviews of the same view
• the text fields have tags in the order you want to progress (e.g., textField2.tag = 2, textField3.tag = 3, etc.)
• moving to the next text field will happen when you tap the return button on the keyboard (you can change this to next, done, etc.)
• you want the keyboard to dismiss after the last text field

Swift 4.1:

extension ViewController: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        let nextTag = textField.tag + 1
        guard let nextTextField = textField.superview?.viewWithTag(nextTag) else {
            textField.resignFirstResponder()
            return false
        }

    nextTextField.becomeFirstResponder()

    return false

    }
}

I have implemented a dynamic solution for navigating through Responders in a view hierarchy. The idea is, to search the whole hierarchy for the next possible responder, forwards or backwards as needed.

UIView Extension for searching:

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;
}

Usage: Add UIToolbar to UITextField / UITextView (in category or subclass):

- (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];
    }
}

Swift 4 for mxcl answer:

txtFirstname.addTarget(txtLastname, action: 
#selector(becomeFirstResponder), for: UIControlEvents.editingDidEndOnExit)