Display UIWebView in custom MonoTouch.Dialog Eleme

问题:

Working on a way to display HTML and RTF content in a custom Element in MonoTouch.Dialog. To get started, I created a new class based on the UIViewElement implementation, with the intention of displaying a UIWebView in a cell (see UIViewElement code here).

The custom element works, but the contents of the UIWebView is never displayed. Once the text of the UIWebView is loaded, I try to resize it using UIWebView.SizeThatFits. This function always return 0s, even though the width given to it (from the actual UITableViewCell it is displayed in) is non-zero.

Is it sufficient to add the UIWebView to the UITableViewCell using this code:

cell.ContentView.AddSubview (webView);

The UIWebView never returns a non-zero height, so the actual cell is never displayed. Even if I override the height calculation and return a static height (such as 100f), the UIWebView is still not displayed.

The element's complete code:

public class RBHTMLRow : Element, IElementSizing
{
    public enum CellFlags {Transparent = 1,DisableSelection = 2}
    public CellFlags Flags;
    private UIWebView webView = null;
    private UITableViewCell current_cell;
    NSString key;

    private void ResizeWebView ()
    {
        if (current_cell != null)
        {
            RectangleF frame = webView.Frame;
            SizeF fittingSize = webView.SizeThatFits(new SizeF(current_cell.Frame.Width, 1f));
            frame.Size = fittingSize;
            webView.Frame = frame;
        }
    }

    private void InitWebView(bool isRTF, string content )
    {
        webView = new UIWebView();
        webView.LoadHtmlString ( content, new NSUrl(""));
        webView.LoadFinished += delegate {
            ResizeWebView();
        } ;
    }

    public RBHTMLRow (bool isRTF, String content, String caption) : base (caption)
    {
        key = new NSString("rbhtml_row");
        InitWebView(isRTF, content);
    }

    protected override NSString CellKey {
    get {
        return key;
    }
    }

    public override UITableViewCell GetCell (UITableView tv)
    {
        var cell = tv.DequeueReusableCell (CellKey);
        if (cell == null){
            cell = new UITableViewCell (UITableViewCellStyle.Default, CellKey);
            if ((Flags & CellFlags.Transparent) != 0){
                cell.BackgroundColor = UIColor.Clear;
                cell.BackgroundView = new UIView (RectangleF.Empty) { 
                    BackgroundColor = UIColor.Clear 
                } ;
            }

            cell.SelectionStyle = UITableViewCellSelectionStyle.None;
            cell.ContentView.AddSubview (webView);
        }  
        current_cell = cell;
        ResizeWebView();
        return cell;
    }

public float GetHeight (UITableView tableView, NSIndexPath indexPath){
    return webView.Bounds.Height;
}