TextBox Scrollbar. Scrolling to end of TextBox within Thread

Question

I've tried all the answers suggest in Stack Overflow to get my scrollbar to move to the bottom as text is being updated, but I have a feeling its not working because it's within a thread. My code is below ...

foreach(HtmlAgilityPack.HtmlNode paginationUser in paginationUsers) {
                    String userUrl = paginationUser.GetAttributeValue("id","");
                    this.Invoke((MethodInvoker)delegate { 
                        txtLog.AppendText("...... Added " + userUrl + Environment.NewLine);
                        txtLog.Select(txtLog.Text.Length, 0);
                        txtLog.ScrollToCaret();

                    });
                }

Is it the thread thats causing the code not to work? And what's a better solution?

Here is one of them ... http://stackoverflow.com/questions/898307/how-do-i-automatically-scroll-to-the-bottom-of-a-multiline-text-box — Sian Jakey Ellis, Oct 31 '11 at 13:18

score 0 · Answer 1 · answered Apr 17 '13 at 17:09

I feel using this code is better:

TextBox.AppendText("your text")

it will automatically scroll to the end of the newly appended text & the auto scrolling animation seems more smoother compared to TextBox.ScrollToCaret() method

you can put this code at TextChanged TextBox event

score 0 · Answer 2 · answered Dec 02 '15 at 21:45

I am having the same problem with WPF, using a thread to write to the textbox. It works fine until I add the ScrollToEnd.

I have no solution, just some remarks.

You are not locking the control. You should if you are filling it from a tread. If I use Invoke it does work (but the UI becomes unresponsive). I use BeginInvoke, which is smoother but then it totally locks up if I use ScrollToEnd.

It seems to be some kind of triggering issue, one event causing the other.

Try feeding text slowly and see what happens, the worker thread may be flooding the textbox, giving it a really hard time, not allowing the main thread to do its thing.

score 0 · Accepted Answer · answered Oct 31 '11 at 14:07

0

Try to add this code :

  TextBox.SelectionStart = txtLogEntries.Text.Length;
  TextBox.ScrollToCaret();

at onTextChanged TextBox event .

answered Oct 31 '11 at 14:07

Rosmarine Popcorn

10,761
11
59
89

TextBox Scrollbar. Scrolling to end of TextBox within Thread

3 Answers3