UITextFieldがキーボードで隠れないようにスクロールアップする方法。 ViewControllerに以下のコードを実装してUITextFieldのdelegateにする

gistfile1.txt

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
   [super viewWillDisappear:animated];

    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardWillHideNotification
                                                  object:nil];
}

#pragma mark - scroll up when keyboard is present

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    // Animate the current view out of the way
    CGPoint p = [self.view.superview convertPoint:sender.frame.origin fromView:self.view];
    if (self.view.superview.bounds.size.height - p.y < 280) {
        offsetForKeyboard = p.y - 100;  // offsetForKeyboardはivar
        
        CGRect r = self.view.frame;
        r.origin.y -= offsetForKeyboard;
        r.size.height = self.view.superview.bounds.size.height + offsetForKeyboard;
        
        [UIView animateWithDuration:0.3 animations:^{
            self.view.frame = r;
        }];
    }
}

-(void)keyboardWillHide
{
    if (0 < offsetForKeyboard) {
        offsetForKeyboard = 0;
        
        [UIView animateWithDuration:0.3 animations:^{
            self.view.frame = self.view.superview.bounds;
        }];
    }
}