Why are my UIScrollView's bounds changed when rotating the device? - uikit

Question

I'm adding my view controller's view to the main window. My view controller's view is a UIScrollView.
The view's bounds are set to 500x500 and the view really is shown with the correct size.
However, if I rotate the device, the scroll view gets maximized and eats up all available scpace.
I do not have an auto resizing mask anywhere, nor do I change the scroll view's bounds.
What is changing the frame/bounds of my scroll view?
this.oPdfController = new PdfViewController(NSUrl.FromFilename("./pdffeatures.pdf"), 2);
this.oPdfController.View.Frame = new RectangleF(new PointF(40, 40), new SizeF(500, 500));
this.oPdfController.View.AutoresizingMask = UIViewAutoresizing.None;
window.AddSubview (this.oPdfController.View);
Here's the source of the controller:
using System;
using MonoTouch.UIKit;
using MonoTouch.CoreAnimation;
using MonoTouch.CoreGraphics;
using MonoTouch.Foundation;
using System.Drawing;
namespace PdfViewerTest
{
public class PdfViewController : UIViewController
{
public PdfViewController (IntPtr handle) : base( handle )
{
}
public PdfViewController (NSUrl oUrl, int iPage) : base( )
{
}
public override bool ShouldAutorotateToInterfaceOrientation (UIInterfaceOrientation toInterfaceOrientation)
{
return true;
}
public override void LoadView ()
{
base.LoadView ();
UIScrollView oScrollView = new UIScrollView (new RectangleF (new PointF (0, 0), new SizeF(1, 1)));
oScrollView.Delegate = new ScrollViewDelegate (this);
oScrollView.MinimumZoomScale = 1.0f;
oScrollView.MaximumZoomScale = 4.0f;
oScrollView.BackgroundColor = UIColor.ScrollViewTexturedBackgroundColor;
this.View = oScrollView;
}
/// <summary>
/// Gets the scroll view.
/// </summary>
private UIScrollView ScrollView
{
get
{
return this.View as UIScrollView;
}
}
/// <summary>
/// Delegate for the scroll view.
/// </summary>
public class ScrollViewDelegate : UIScrollViewDelegate
{
public ScrollViewDelegate (PdfViewController oParentController) : base( )
{
this.oParentController = oParentController;
}
private PdfViewController oParentController;
public override UIView ViewForZoomingInScrollView (UIScrollView scrollView)
{
// Not implemented here.
return null;
}
}
}
}

Answer 1

I think this strange behaviour is due to oScrollView becoming a direct subview of the window.
I just tested your code and couldn't find a solution to keep the good size with this view structure, but a simple workaround is to add oScrollView as a subview of PdfViewController.View (just tested (on simulator), size stays the same even when rotating).
This way, your first code block should become :
this.oPdfController = new PdfViewController(NSUrl.FromFilename("pdffeatures.pdf"), 2);
window.AddSubview (this.oPdfController.View);
and your controller :
using System;
using MonoTouch.UIKit;
using MonoTouch.CoreAnimation;
using MonoTouch.CoreGraphics;
using MonoTouch.Foundation;
using System.Drawing;
namespace PdfViewerTest
{
public class PdfViewController : UIViewController
{
UIScrollView oScrollView = null;
public PdfViewController (IntPtr handle) : base( handle )
{
}
public PdfViewController (NSUrl oUrl, int iPage) : base( )
{
}
public override bool ShouldAutorotateToInterfaceOrientation (UIInterfaceOrientation toInterfaceOrientation)
{
return true;
}
public override void LoadView ()
{
base.LoadView ();
oScrollView = new UIScrollView (new RectangleF (new PointF (0, 0), new SizeF(1, 1)));
oScrollView.Delegate = new ScrollViewDelegate (this);
oScrollView.MinimumZoomScale = 1.0f;
oScrollView.MaximumZoomScale = 4.0f;
oScrollView.BackgroundColor = UIColor.ScrollViewTexturedBackgroundColor;
oScrollView.Frame = new RectangleF(new PointF(40, 40), new SizeF(500, 500));
oScrollView.AutoresizingMask = UIViewAutoresizing.None;
this.View.AddSubView(oScrollView);
}
/// <summary>
/// Gets the scroll view.
/// </summary>
private UIScrollView ScrollView
{
get
{
return oScrollView;
}
}
/// <summary>
/// Delegate for the scroll view.
/// </summary>
public class ScrollViewDelegate : UIScrollViewDelegate
{
public ScrollViewDelegate (PdfViewController oParentController) : base( )
{
this.oParentController = oParentController;
}
private PdfViewController oParentController;
public override UIView ViewForZoomingInScrollView (UIScrollView scrollView)
{
// Not implemented here.
return null;
}
}
}
}
HTH