Question

I’m trying to make a custom scroll bar for Web browser Control.

I used a Scroll Bar Control for this,so i attached Scroll Bar Control to Web browser Control
use following code:

        Doc = (mshtml.HTMLDocument)browser.Document;
        Doc.parentWindow.document.body.style.overflow = "hidden";
        mshtml.IHTMLElement2 ScrolablePlace= (mshtml.IHTMLElement2)Doc.getElementById("ScrolablePlace");
        ScrollBar.ViewportSize = browser.ActualHeight;
        ScrollBar.Maximum = ScrolablePlace.scrollHeight;

and while scroling scrolbar:

 private void ScrollBar_Scroll(object sender, ScrollEventArgs e)
        {
            if (Doc != null)
            {
                Doc.parentWindow.scroll(0, (int)e.NewValue);
            }
        }

this is work,but ScrollBar.Maximum value is always larger than scroll bar place.dose ScrollBar.ViewportSize and ScrollBar.Maximum
set correctly?

I Hope i could explain my problem correctly with this image:

Answer 1

After some research, I’ve found that a scroll bar maximum property must calculate from this formula :

scrolbar.maximum=(maxsize-scrolbar.ViewportSize)+scrolbar.smallchanges

so i simply do this and it work fine:

   ScrollBar.Maximum = ScrolablePlace.scrollHeight- browser.ActualHeight+ScrollBar.SmallChange;