I have a c# winform application, the form contains a panel to show ads of any type (video, image, pdf), everything works good except for the pdf files, since I have to set

ZoomMode.FitWidth 

(client’s requirement). this setup results to show only the first part of each page.

to solve this issue I tried multiple solutions:

1. adding the pdf to the panel and a timer (pdf size set to panel.width and pdf file height –PageSize.height * PageCount) the timer starts and the panel.verticalScroll.value increases by one on each interval ==> the panel vertical scroll ends way before the the pdf ending. (the condition to stop the timer is

commissionsPanel.VerticalScroll.Value >= commissionsPanel.VerticalScroll.Maximum - commissionsPanel.VerticalScroll.LargeChange + 1

2. Scrolling only the pdf file using

pdfViewer.Renderer.PerformScroll(ScrollAction.LineDown, Orientation.Vertical);

works fine but I can’t detect the very ending of the file, I can only fine the last page of the file, but since the ZoomMood.FitWidth only the top part of the page appears.

3. Adding a custom vScrollBar give it the pdf height as maximum value and increase it by one on each line down scrolling.

if (vScrollBar.Value <= vScrollBar.Maximum)
            {
                vScrollBar.Value++;
                pdfViewer.Renderer.PerformScroll(ScrollAction.LineDown, Orientation.Vertical);
            }
else
            {
                timerPdfcommissions.Stop();
                MessageBox.Show("End Of File!");
            }

the pdf ends way before the maximum value of the verticalScrollBar which leads to a very long waiting period.

4. there is no EOF in the library and can’t use the EOF marker in this context.

5. extracting the text or detecting the lines in the file doesn’t work if the pdf contains photos.

I tried so many hicks but nothing works. any help would be really appreciated, any tips to find the end of the file, please!