This question has already been answered:

There is a form, on it RichTextBox, which displays the progress.

That is, append messages are made of the form: "1/100 files copied \ n"

So, when the number of lines reaches about 60,000, it becomes clear that the messages are not added immediately, as in the beginning, but with a delay.

If it is cleared, the speed returns.

Is it possible that 60,000 lines cause sagging?

How to deal with it?

Reported as a duplicate by the participants andreycha , rdorn , aleksandr barakin , user194374, Denis 25 Aug '16 at 6:08 .

A similar question was asked earlier and an answer has already been received. If the answers provided are not exhaustive, please ask a new question .

    1 answer 1

    This question has already been discussed: one , two .

    In short, the RichTextBox Winform is not intended for this amount of data. How to fight - do not display such a volume. If these are logs, then such a volume is simply not needed by the user. If this is a text editor - display only part of the content and change it on the scroll.

    In your case, you can have only one line and change its contents.