Checking if a Windows forms scroll bar is scrolled all the way down?

Question

I have a rich text box which serves as a log. The log automatically scrolls itself down when a new message is appended, which is good. The only problem is when the user wants to view something in the log from before; if a new message is appended, the box automatically scrolls all the way down and prevents the user from seeing anything. I would like to be able to check if the rich text box is scrolled all the way down, and if it isn't not scroll down.

Currently I can get the scroll position in the virtual text space (SendMessage with EM_GETSCROLLPOS). I can also get scroll bar info with GetScrollBarInfo pinvoke. But how do I figure out what the bottom of the virtual text space is?

Thanks!

Wouln't it be more intuitive if you check whether the end of the text is in the visible area? — TheBlastOne, Mar 09 '11 at 13:57
Ergh, SendMessage with WM_GETTEXT is all that I remember. Have to dig it out, don't have that at hand right now, sorry, but will try to dig it out today or so. — TheBlastOne, Mar 14 '11 at 07:29

Saeb Amini · Answer 1 · 2011-03-09T14:15:45.360

2

Use a vScrollBar control for your RichTextBox and handle its Scroll event

    private void vScrollBar1_Scroll(object sender, ScrollEventArgs e)
    {
        if (e.Type == ScrollEventType.Last)
        {
            //scrollbar is all the way down
        }
        else
        {
            //user has scrolled up
        }
    }

edited Mar 09 '11 at 14:15

answered Mar 09 '11 at 13:54

Saeb Amini

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Checking if a Windows forms scroll bar is scrolled all the way down?

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