troubles with header and footer

[Mathieu]

Hello ,

I try to add custom header and footer  in a radDocument, but when I do , i can only write a single page . When going to the second page the editor disappears here's the function i'd like to use 

public void InsertPageLayout()
        {
            Section section = this.RichTextBox.Document.Sections.First;
            section.HasDifferentFirstPageHeaderFooter = false;
            this.RichTextBox.Document.HasDifferentEvenAndOddHeadersFooters = false;
            RadDocument footerBody = new RadDocument();

            footerBody.LineSpacing = 1.15;
            footerBody.ParagraphDefaultSpacingBefore = 5;
            footerBody.ParagraphDefaultSpacingAfter = 5;
            footerBody.SectionDefaultPageMargin = new Padding(95);

            Section sectionF = new Section();
            Paragraph p = new Paragraph();
            Span s = new Span();
            s.Text = "Footer";
            p.Inlines.Add(s);
            sectionF.Blocks.Add(p);

            RadDocument headerBody = new RadDocument();
            headerBody.LineSpacing = 1.15;
            headerBody.ParagraphDefaultSpacingBefore = 5;
            headerBody.ParagraphDefaultSpacingAfter = 5;
            headerBody.SectionDefaultPageMargin = new Padding(95);
            Section sectionH = new Section();
            Paragraph ph = new Paragraph();
            //ph.LeftIndent = 0;
            ImageInline im = new ImageInline(this.GetResourceUri("images/Lighthouse.jpg"));


            /*if (im.UriSource == null
            {
                BitmapImage imSource = new BitmapImage();
            }*/


            double pixelHeight = im.ImageSource.PixelHeight;
            double pixelWidth = im.ImageSource.PixelWidth;

            double proportion = pixelHeight / pixelWidth;
            bool portrait = true;
            double largeur;
            if (portrait)
            {
                largeur = 21 / 0.0264;
            }
            else
            {
                largeur = 29.7 / 0.0264;
            }

            double margeHaut = 1;
            double margeBas = 1;
            double margeGauche = 1 / 0.0264;
            double margeDroite = 12 / 0.0264;

            double largeurImg = largeur - (margeGauche + margeDroite);
            double hauteurImg = largeurImg * proportion;

            // Convertir cm en unité px
            im.Width = largeurImg;
            im.Height = hauteurImg;

            Span sh = new Span();
            sh.Text = "Header";
            //ph.Inlines.Add(im);
            ph.Inlines.Add(sh);
            sectionH.Blocks.Add(ph);
            //sectionH.ActualPageMargin = new Padding(0, 0, 0, 0);
            headerBody.Sections.Add(sectionH);
            footerBody.Sections.Add(sectionF);

            Header header = new Header() { Body = headerBody, IsLinkedToPrevious = false };

            Footer footer = new Footer() { Body = footerBody, IsLinkedToPrevious = false };
            //document is an instance of RadDocument, representing the content of the footer,

            //document is an instance of RadDocument, representing the content of a Header,
            //typically contains a few paragraphs
            //section.Headers.First = header;
            //section.Footers.First = footer;


            //header.Body.InsertReadOnlyRange(startPosition:new DocumentPosition(headerBody), endPosition:new DocumentPosition(headerBody));
            //footer.Body.InsertReadOnlyRange(startPosition: new DocumentPosition(footerBody), endPosition: new DocumentPosition(footerBody));

            RadDocument footerBody2 = new RadDocument();
            Section sectionF2 = new Section();
            Paragraph pf2 = new Paragraph();
            Span sf2 = new Span();
            sf2.Text = "Footer 2";
            pf2.Inlines.Add(sf2);
            sectionF2.Blocks.Add(pf2);

            RadDocument headerBody2 = new RadDocument();
            Section sectionH2 = new Section();
            Paragraph ph2 = new Paragraph();


            //ph2.Inlines.Add(im);

            Span sh2 = new Span();
            sh2.Text = "Header 2";
            ph2.Inlines.Add(sh2);
            sectionH2.Blocks.Add(ph2);
            headerBody2.Sections.Add(sectionH2);

            Header header2 = new Header() { Body = headerBody2, IsLinkedToPrevious = true };
            Footer footer2 = new Footer() { Body = footerBody2, IsLinkedToPrevious = true };

            //Section section2 = new Section();
            //section2.Blocks.Add(new Paragraph());

            //section.Headers.Even = header2;
            //section.Footers.Even = footer2;
            //section.Headers.Default = header;
            //section.Footers.Default = footer;
            this.RichTextBox.UpdateFooter(section, HeaderFooterType.Default, footer);
            this.RichTextBox.UpdateHeader(section, HeaderFooterType.Default, header);

            this.InsertPageLayoutResponseComplete(this, null);
        }

public event DownloadStringCompletedEventHandler InsertPageLayoutResponseComplete;
        private void OnInsertPageLayoutResponseComplete(object sender, DownloadStringCompletedEventArgs e)
        {
            if (InsertPageLayoutResponseComplete != null)
            {
                InsertPageLayoutResponseComplete(this, e);
            }
        }

The exeption is 

Uncaught Error: Unhandled Error in Silverlight Application
Code: 4004
Category: ManagedRuntimeError
Message: System.NullReferenceException: La référence d'objet n'est pas définie à une instance d'un objet.
   à Telerik.Windows.Documents.Model.RadDocument.get_ParagraphDefaultSpacingBefore()
   à Telerik.Windows.Documents.Model.RadDocument.CopyPropertiesFromOverride(DocumentElement element)
   à Telerik.Windows.Documents.Model.DocumentElement.CopyPropertiesFrom(DocumentElement fromElement)
   à Telerik.Windows.Documents.Model.DocumentElement.CreateElementCopy()
   à Telerik.Windows.Documents.Model.DocumentElement.CreateShallowCopy(DocumentElement documentElement)
   à Telerik.Windows.Documents.Model.DocumentElement.CreateShallowCopy()
   à Telerik.Windows.Documents.Model.DocumentElement.CreateDeepCopy(DocumentElement root)
   à Telerik.Windows.Documents.Model.DocumentElement.CreateDeepCopy()
   à Telerik.Windows.Documents.Model.RadDocument.CreateDeepCopy(Boolean copyStyles)
   à Telerik.Windows.Documents.UI.HeaderPresenter.GetBody()
   à Telerik.Windows.Documents.UI.HeaderFooterPresenterBase.UpdateBody()
   à Telerik.Windows.Documents.UI.HeaderFooterPresenterBase.OnApplyTemplate()
   à System.Windows.FrameworkElement.OnApplyTemplate(IntPtr nativeTarget)

:



Thank you for your attention.

Mathieu