Question

How can I code two buttons for scrolling into a RichTextBox up and down ? What I try :

private void btnScrollTop_Click(object sender, EventArgs e) {
            if (rtbDefinitie.SelectionStart >= 30) {
                rtbDefinitie.SelectionStart -= 30;
                rtbDefinitie.ScrollToCaret();
            }
        }
private void btnScrollBottom_Click(object sender, EventArgs e) {
            if (rtbDefinitie.SelectionStart <= 30) {
                rtbDefinitie.SelectionStart += 30;
                rtbDefinitie.ScrollToCaret();
            }
        }

But it’s seems to get stuck after I press scroll down button twice. What I need to do ?

Answer 1

The second click seems to be interpreted as DoubleClick, so you could just register this event too and put the same code behind it (or replace the 30 by 60)

EDIT:
If the Application stucks, because it’s working and does not have the time to update the GUI, you could try to call Application.DoEvents(); after every raised Clickevent:

private void btnScrollBottom_Click(object sender, EventArgs e) {
            if (rtbDefinitie.SelectionStart <= rtbDefinitie.TextLength) {
                rtbDefinitie.SelectionStart += 30;
                rtbDefinitie.ScrollToCaret();
                Application.DoEvents();
            }
        }