Question

I required a custom tab-switching view for my application, so i made a .xib with a UIScrollView and a UITabBar.

I added a ‘ClearChildren’ and a ‘SwitchViews’ method to the UIScrollView like this :

public static class Extensions
{
    #region UIScrollView extensions
    public static void ClearChildren (this UIScrollView scrollViewer)
    {
        foreach(var subview in scrollViewer.Subviews)
        {
            subview.RemoveFromSuperview();
        }
    }

    /// <summary>
    /// switches the content views of a UIScrollView entirely
    /// with for example a tab-bar.
    /// </summary>
    /// <param name="scrollViewer">
    /// A <see cref="UIScrollView"/>
    /// </param>
    /// <param name="newView">
    /// A <see cref="UIView"/>
    /// </param>
    public static void SwitchViews (this UIScrollView scrollViewer, UIView newView)
    {

        scrollViewer.ClearChildren();
        scrollViewer.AddSubview(newView);



        //reset content size
        scrollViewer.ContentSize = new System.Drawing.SizeF(newView.Bounds.Width, newView.Bounds.Height);

    }


    #endregion
}

however, when i switch the views on a UIScrollView using someUiScrollView.SwitchViews(someOtherScrollView)
The UIScrollView suddenly loses its scroll bars and allows both horizontal and vertical scrolling.

how do i make sure the horizontal and vertical scrolling behavior of the UIScrollView do not change, and keep my scrollbars visible?

Answer 1

The view i was loading turned out to be a little bit wider than the UIScrollView.

If this could be prevented simply by setting the new view’s width to the bounds of the UIScrollView like so :

...
            scrollViewer.ClearChildren();
            newView.Bounds = new System.Drawing.RectangleF(new PointF(0f,0f), new SizeF(scrollViewer.Bounds.Width, newView.Bounds.Height));
            scrollViewer.AddSubview(newView);
...

(naturally this means the view can have vertical scrolling only, which is what i wanted in this particular example)