Get UITableView to scroll to the selected UITextField and Avoid Being Hidden by Keyboard

In my app, I have successfully used a combination of contentInset and scrollToRowAtIndexPath like this:

When you want to display the keyboard, just add a contentInset at the bottom with your table with desired height:

tableView.contentInset =  UIEdgeInsetsMake(0, 0, height, 0);

Then, you can safely use

[tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:cell_index inSection:cell_section] animated:YES];

By adding the contentInset, even if you are focusing on the last cell the tableView will still be able to scroll. Just make sure that when you are dismissing the keyboard, you reset the contentInset.

EDIT:
If you have only one section (you can replace cell_section with 0) and the use the textView tag to inform the cell row.

Swift

@objc private func keyboardWillShow(_ notification: Notification) {
    guard let userinfo = notification.userInfo else {
        return
    }

    guard
        let duration = (userinfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue,
        let endFrame = (userinfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue,
        let curveOption = userinfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt else {
            return
    }
    
    UIView.animate(withDuration: duration, delay: 0, options: [.beginFromCurrentState, .init(rawValue: curveOption)], animations: {
        let edgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: endFrame.height, right: 0)
        self.scrollView.contentInset = edgeInsets
        self.scrollView.scrollIndicatorInsets = edgeInsets
    })
}

@objc private func keyboardWillHide(_ notification: Notification) {
    guard let userinfo = notification.userInfo else {
        return
    }

    guard
        let duration = (userinfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue,
        let curveOption = userinfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt else {
            return
    }
    
    UIView.animate(withDuration: duration, delay: 0, options: [.beginFromCurrentState, .init(rawValue: curveOption)], animations: {
        let edgeInsets = UIEdgeInsets.zero
        self.scrollView.contentInset = edgeInsets
        self.scrollView.scrollIndicatorInsets = edgeInsets
    })
}


override func viewDidLoad() {
    super.viewDidLoad()
    
    // ...

    subscribeToKeyboardNotifications()
}

deinit {
    unsubscribeFromKeyboardNotifications()
}

private func subscribeToKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIWindow.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIWindow.keyboardWillHideNotification, object: nil)
}

private func unsubscribeFromKeyboardNotifications() {
    NotificationCenter.default.removeObserver(self, name: UIWindow.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIWindow.keyboardWillHideNotification, object: nil)
}

Objective C

- (void)keyboardWillShow:(NSNotification *)sender
{
    CGFloat height = [[sender.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
    NSTimeInterval duration = [[sender.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationOptions curveOption = [[sender.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] unsignedIntegerValue] << 16;
    
    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionBeginFromCurrentState|curveOption animations:^{
        UIEdgeInsets edgeInsets = UIEdgeInsetsMake(0, 0, height, 0);
        tableView.contentInset = edgeInsets;
        tableView.scrollIndicatorInsets = edgeInsets;
    } completion:nil];
}

- (void)keyboardWillHide:(NSNotification *)sender
{
    NSTimeInterval duration = [[sender.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationOptions curveOption = [[sender.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] unsignedIntegerValue] << 16;

    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionBeginFromCurrentState|curveOption animations:^{
        UIEdgeInsets edgeInsets = UIEdgeInsetsZero;
        tableView.contentInset = edgeInsets;
        tableView.scrollIndicatorInsets = edgeInsets;
    } completion:nil];
}

And in - (void)viewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

Then

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

This is a tweak to FunkyKat's answer (big thank you FunkyKat!). It would probably be beneficial to not hardcode UIEdgeInsetsZero for future iOS compatibility.

Instead, I ask for the current inset value and tweak the bottom value as needed.

- (void)keyboardWillShow:(NSNotification *)sender {
    CGSize kbSize = [[[sender userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    NSTimeInterval duration = [[[sender userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    CGFloat height = UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]) ? kbSize.height : kbSize.width;
    if (isIOS8()) height = kbSize.height;

    [UIView animateWithDuration:duration animations:^{
        UIEdgeInsets edgeInsets = [[self tableView] contentInset];
        edgeInsets.bottom = height;
        [[self tableView] setContentInset:edgeInsets];
        edgeInsets = [[self tableView] scrollIndicatorInsets];
        edgeInsets.bottom = height;
        [[self tableView] setScrollIndicatorInsets:edgeInsets];
    }];
}

- (void)keyboardWillHide:(NSNotification *)sender {
    NSTimeInterval duration = [[[sender userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    [UIView animateWithDuration:duration animations:^{
        UIEdgeInsets edgeInsets = [[self tableView] contentInset];
        edgeInsets.bottom = 0;
        [[self tableView] setContentInset:edgeInsets];
        edgeInsets = [[self tableView] scrollIndicatorInsets];
        edgeInsets.bottom = 0;
        [[self tableView] setScrollIndicatorInsets:edgeInsets];
    }];
}