Answers

• DavidOlubajo GBMember ✭

  June 2016

  Update: Here's a more simplified and complete UIViewController that demonstrates this issue:

  The buttons never get centered !!!

  public class ViewController : UIViewController
  {
      UIScrollView scrollView;
      UIStackView stackView;
  
  public override void ViewDidLoad ()
  {
      base.ViewDidLoad ();
  
      View.BackgroundColor = UIColor.White;
  
      scrollView = new UIScrollView ();
      scrollView.TranslatesAutoresizingMaskIntoConstraints = false;
      View.AddSubview (scrollView);
  
      View.AddConstraints (
          NSLayoutConstraint
          .FromVisualFormat (
              "H:|[scrollView]|",
              NSLayoutFormatOptions.AlignAllCenterX,
              new NSDictionary (),
              NSDictionary.FromObjectAndKey (scrollView, new NSString ("scrollView"))
          )
      );
  
      View.AddConstraints (
          NSLayoutConstraint
          .FromVisualFormat (
              "V:|[scrollView]|",
              NSLayoutFormatOptions.AlignAllCenterX,
              new NSDictionary (),
              NSDictionary.FromObjectAndKey (scrollView, new NSString ("scrollView"))
          )
      );
  
      stackView = new UIStackView ();
      stackView.TranslatesAutoresizingMaskIntoConstraints = false;
      stackView.Axis = UILayoutConstraintAxis.Vertical;
      stackView.Alignment = UIStackViewAlignment.Trailing;
      scrollView.AddSubview (stackView);
  
      scrollView.AddConstraints (
          NSLayoutConstraint
          .FromVisualFormat (
              "H:|[stackView]|",
              NSLayoutFormatOptions.AlignAllCenterX,
              new NSDictionary (),
              NSDictionary.FromObjectAndKey (stackView, new NSString ("stackView"))
          )
      );
  
      scrollView.AddConstraints (
          NSLayoutConstraint
          .FromVisualFormat (
              "V:|[stackView]|",
              NSLayoutFormatOptions.AlignAllCenterX,
              new NSDictionary (),
              NSDictionary.FromObjectAndKey (stackView, new NSString ("stackView"))
          )
      );
  
      for (var i = 0; i < 100; i++) {
          var vw = new UIButton (UIButtonType.System);
          vw.SetTitle ("Button", UIControlState.Normal);
          stackView.AddArrangedSubview (vw);
      }
  }
  }
  

  0
• DavidOlubajo GBMember ✭

  June 2016 Accepted Answer

  I've fixed this issue now: an extra equal width constraint between the scrollView and the stackView.

  scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[stackView(==scrollView)]", options: .AlignAllCenterX, metrics: nil, views: ["stackView": stackView, "scrollView": scrollView]))
  

  5