windows phone richtextbox hyperlink remove underline

        private void AppendLink(string text, Uri uri)

        {

            Paragraph paragraph;

            if (this.Blocks.Count == 0 ||

                (paragraph = this.Blocks[this.Blocks.Count - 1] as Paragraph) == null)

            {

                paragraph = new Paragraph();

                this.Blocks.Add(paragraph);

            }

            var run = new Run { Text = processHTMLEntity(text.Replace("<em>", "").Replace("</em>", "")) };           

            run.Foreground = new SolidColorBrush(new Color() {A = 0xFF, R = 0x6a, G = 0x9b, B = 0xCD }); 

            var link = new Hyperlink { NavigateUri = uri };

            link.Inlines.Add(run);

            link.TextDecorations = null;

            link.Click += (sender, e) =>

                {

                    var lk = sender as Hyperlink;

                    new Microsoft.Phone.Tasks.WebBrowserTask() { Uri = lk.NavigateUri }.Show();

                };

            paragraph.Inlines.Add(link);

        }

link.TextDecorations = null; 即移除hyperlink的underline.