UITextView is not scrolled to top when loaded

Question

When I have text that does not fill the UITextView, it is scrolled to the top working as intended. When there is more text than will fit on screen, the UITextView is scrolle

Answer 1

For iOS9 and later the textview even on viewWillAppear: is coming with CGRect(0,0,1000,1000). In order for this to work you have to call in viewWillAppear:

[self.view setNeedsLayout];
[self.view layoutIfNeeded];
// * Your code here

After that the textview will have correct CGRect data and you can perform any scrolling operation you may need.

Answer 2

The problem with putting code in viewDidLayoutSubviews and viewWillLayoutSubviews is that these methods are called a lot (during device rotation, resizing views etc ...). If you're reading something from text view, and you rotate the device, you expect that the part of the content you're viewing stays on screen. You do not expect that it scrolls back to top. Instead of scrolling the content to top, try to keep text view's scrollEnabled property set to NO (false), and turn it back on in viewDidAppear.

Answer 3

Swift

self.textView.scrollRangeToVisible(NSMakeRange(0, 0))

Objective-C

[self.textView scrollRangeToVisible:(NSMakeRange(0, 0))];

Answer 4

i had same issue! Reset to suggested constrains and just put (y offset)

@IBOutlet weak var textContent: UITextView!

    override func viewDidLoad() {
        textContent.scrollsToTop = true
        var contentHeight = textContent.contentSize.height
        var offSet = textContent.contentOffset.x
        var contentOffset = contentHeight - offSet
        textContent.contentOffset = CGPointMake(0, -contentOffset)
    }

Answer 5

UITextView is a subclass of UIScrollView, so you can use its methods. If all you want to do is ensure that it's scrolled to the top, then wherever the text is added try:

[self.mainTextView setContentOffset:CGPointZero animated:NO];

EDIT: AutoLayout with any kind of scrollview gets wonky fast. That setting a fixed width solves it isn't surprising. If it doesn't work in -viewDidLayoutSubviews then that is odd. Setting a layout constraint manually may work. First create the constraints in IB:

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *textViewWidthConstraint;
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *textViewHeightConstraint;

then in the ViewController

    -(void)updateViewConstraints {
            self.textViewWidthConstraint.constant = self.view.frame.size.width - 40.0f;
            self.textViewHeightConstraint.constant = self.view.frame.size.height - 40.0f;
            [super updateViewConstraints];
        }

May still be necessary to setContentOffset in -viewDidLayoutSubviews.

(Another method would be to create a layout constraint for "'equal' widths" and "'equal' heights" between the textView and its superView, with a constant of "-40". It's only 'equal' if the constant is zero, otherwise it adjusts by the constant. But because you can only add this constraint to a view that constraints both views, you can't do this in IB.)

You may ask yourself, if I have to do this, what's the point of AutoLayout? I've studied AutoLayout in depth, and that is an excellent question.

Answer 6

It seems like a terrible idea to handle this issue in code in the view controller because: A. The view controller isn't making any mistake or doing anything wrong, and B, if you have more than one view controller with a wrongly scrolled text view, you end up with redundant code. The solution should be to write code that exists in the text view class. My solution works with Interface Builder where I simply select a custom class for the UITextView and use this class:

import Foundation
import UIKit

class TopTextView: UITextView {
    var scrolled = false

    override func layoutSubviews() {
        super.layoutSubviews()
        if scrolled { return }
        setContentOffset(.zero, animated: false)
        scrolled = true
    }
}

This worked for me. I happen to have a view controller with a child view with a UITextView as a child of that view, not with a UITextView as the child of the view controller. I don't know how well this works if the text view is under top or bottom bars but since no edge insets are touched, this should work.