private async void btnRender_Click(object sender, RoutedEventArgs e)
{
await Task.Delay(TimeSpan.FromMilliseconds(100));
pdf.Clear();
progressRing.IsActive = true;
panel.Arrange(pdf.PageRectangle);
//1. Export UI as an image and then draw this image in pdf document.
var renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(panel);
var wb = new WriteableBitmap(renderTargetBitmap.PixelWidth, renderTargetBitmap.PixelHeight);
(await renderTargetBitmap.GetPixelsAsync()).CopyTo(wb.PixelBuffer);
var rect = new Rect(0, 0, renderTargetBitmap.PixelWidth, renderTargetBitmap.PixelHeight);
pdf.DrawImage(wb, rect);
//2. Draw every UI elements inside the panel in pdf document.
//await pdf.DrawElement(panel, pdf.PageRectangle);
PdfUtils.SetDocumentInfo(pdf, Strings.RenderUIDocumentTitle);
await pdfDocSource.LoadFromStreamAsync(PdfUtils.SaveToStream(pdf).AsRandomAccessStream());
progressRing.IsActive = false;
}
async void TOCPage_Loaded(object sender, RoutedEventArgs e)
{
progressRing.IsActive = true;
CreateDocumentTOC(pdf);
PdfUtils.SetDocumentInfo(pdf, Strings.TableOfContentsDocumentTitle);
await pdfDocSource.LoadFromStreamAsync(PdfUtils.SaveToStream(pdf).AsRandomAccessStream());
progressRing.IsActive = false;
}