UIScrollView xcode 8 swift 3 - ios

Question

This is my first question and I am brand new to coding.
I'm creating an app and one of the pages has a form for a user to fill out with two labels, two textfields, a switch and a "send" button.
For smaller screen sizes, some elements were disappearing, so I used a stackview, but when the keyboard comes up, it blocks the textfield which will be annoying to the user, I'm sure.
I've seen a few tutorials about adding scrollviews, but setting the height so everything fits nicely for smallest devices leaves an uncomfortably large blank area at the bottom of larger screens.
Is there a way to enable the scroll view only when it is needed? Is this what "dynamic" is for?

Answer 1

If your issue is with UI formatting on different sized screens, auto layout is a built in feature in xcode that addresses this. By adding constraints to your views, autolayout will do its best to resize your UI elements so that what you see in storyboard is what you get across all devices. Using this technique you may be able to avoid a scrollview altogether. Try selecting all your views, then go to Editor -> Resolve Auto Layout Issues -> Reset to Suggested Constraints, and see if that works.

Answer 2

Seems that you have two questions. First one is "For smaller screen sizes, some elements were disappearing". That one is answered by #Dalton Sweeney. Use Auto Layout then Reset to Suggested Constraints
I am going to answer your second question, what you are supposed to do when the keyboard covers some UIElemnts.
You don't need to change view controller, you should dynamically change view's frame when the keyboard hides/appears. I made a demo in GitHub, check the full version if you want:https://github.com/EricZhang90/IOS_Demo/tree/master/KeyboadDemo
The main workflow is following:
1) create two notifications to detect the keyboard is about to hide/appear:
- (void)viewDidLoad {
[super viewDidLoad];
NSNotificationCenter *ctr = [NSNotificationCenter defaultCenter];
[ctr addObserver:self
selector:#selector(moveKeyboardInResponseToWillShowNotification:)
name:UIKeyboardWillShowNotification
object:nil];
[ctr addObserver:self
selector:#selector(moveKeyboardInResponseToWillHideNotification:)
name:UIKeyboardWillHideNotification
object:nil];
}
2) adjust view's frame
The method takes two parameters: the first is keyboard information sent from notification center. You can get it from the method in first step. The second parameter indicates this adjustment is about to reduce or expand frame. Its value is 0 when the keyboard is about to hide, and is frame of keyboard when the keyboard is about to appear.
-(void)adjustView: (NSDictionary *)info :(CGRect)rect{
// get duration of keyboard appears/hides
CGFloat duration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
// get keyboard's curve
UIViewAnimationCurve curve = [[info objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
[self.view layoutSubviews];
// Start to adjust frame:
// Animate:
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:duration];
[UIView setAnimationCurve:curve];
[UIView setAnimationBeginsFromCurrentState:YES];
// self.buttonLayoutConstraint is the layout constraint between bottom of view and bottom of screen(super view).
// This is the most important part.
self.buttonLayoutConstraint.constant = rect.size.height;
[self.view layoutSubviews];
[UIView commitAnimations];
}

Answer 3

This is what ended up working for me in terms of moving the scrollview up and out of the way when the textView was selected and activated the keyboard.
func textViewDidBeginEditing(_ textView: UITextView) {
scrollView.setContentOffset(CGPoint(x: 0, y: 50), animated: true)
}
**The 50 value was just what worked for my layout...that number may be different for you.
I also put in:
func textViewDidEndEditing(_ textView: UITextView) {
scrollView.setContentOffset(CGPoint(x: 0, y: 0), animated: true)
}
...so that the scrollview returned to normal once the user is done editing.