Last Updated: 22 Jul 2020 15:42 by ADMIN
Created on: 17 Jul 2020 08:56
Category: SyntaxEditor
Type: Bug Report
Programmatically created Selection persists when contents are deleted via UI

A programmatically created selection keeps highlighting the following part of the text when its original content is deleted via keyboard.

If there are less characters left than the selection encompassed, further editing will result in unhandled Exceptions.

 Steps to reproduce:

  1. Enter multiple lines of text in RadSyntaxEditor
  2. Programmatically set Selection.
  3. Press [Del] or [Backspace] or [Ctrl-X] to remove the selected Text.
Posted on: 22 Jul 2020 07:56

Hi Nadya,


thank you for your prompt answer and insights. Upgrading to 2020.2.616 does indeed fix the problem.


Thanks again and have a nice day! 

Nadya | Tech Support Engineer
Posted on: 17 Jul 2020 14:03

Hello, Christian,

Thank you for writing.

I noticed that the product version that you specify is 2020.1.113. Could you please confirm that you are using this version. I tested it with the same version and was able to observe the same behavior on my end.

However, I would like to note that we have introduced some fixes regarding selected text in RadSyntaxEditor in our next release R1 2020 SP1 (version 2020.1.218). When I test the provided project with the latest version the issue does not occur, and the selection does not highlight the following part of the text. You can check the result with the latest version in the attached gif file. Is it possible to download 2020.1.218 or later version and see how it works now?

We always strive to encourage our customers to upgrade to as latest version as possible. Thus, you can benefit from all the introduced improvements and bug fixes. Note, the latest version is 2020.2.616.

I hope this information helps. Let me know if you have further questions.

Progress Telerik

Attached Files:
Posted on: 17 Jul 2020 09:35

I looks like the selection does not need to be created programmatically. Apparently, to trigger this behaviour, the selection must

  • span multiple lines
  • not be reversed (caret is at end of selection)
  • contain more characters than are left in the text after it.