Syntax editor becomes slow and scroll is choppy

SyntaxEditor for Universal Windows Forum

The latest build of this product (v2018.1 build 0332) was released 1 month ago, which was before this thread was created.
Posted 28 days ago by Rohit
Version: 17.2.0320

The editor and scroll works fine if I have short text in each line, but it is very choppy and slow when every line contains long text.


If I have Lorem; i.e. less than 20 characters in a line and over 1200 of such lines, scroll is smooth and okay (acceptably fast). Editor works fine.

But if I add Lorem Ipsum Porem, Lorem Ipsum Porem, Lorem Ipsum Porem,..... Lorem, Ipsum, Porem; i.e. over 220 characters in each line and just over 40 of such lines in editor, then editor becomes slow. That includes, loading of such text in editor, vertical-horizontal scroll, modifying text of a line and other similar operations. 

We have an application where user can have up to 75000 lines in single instance. Application will be run on a windows 10 tablet with 2GB RAM.

Can you please help me figure out the root cause and fix to this problem, sooner ?

Comments (3)

Posted 28 days ago by Actipro Software Support - Cleveland, OH, USA


The UWP SyntaxEditor's performance is currently hampered a bit by its implementation.  When we originally wrote it for WinRT (before UWP), we had to use multiple TextBlock controls to render text in the editor since there was no other way to do so.  We effectively are adding/updating/removing TextBlocks constantly as you type and scroll.

Later on, Win2D was added by Microsoft which allows for fast text rendering, but it's a massive change to switch to it.  We have already done this switch to Win2D as part of the "SyntaxEditor vNext" project described in our blog, which will end up being the 2019.1 version of the UWP SyntaxEditor.  I suspect this will fix the performance issues you see since creating/updating/removing TextBlock elements like we currently have to do in the 2018.1 UWP version is a performance bottleneck.  And editing/scrolling in the UWP vNext version is super-fast. 

Keep an eye on our blog for more vNext news, as we will eventually be asking for beta testers.  Feel free to e-mail us at our support address if you'd like to sign up ahead of time to be a UWP vNext beta tester.

Actipro Software Support

Posted 25 days ago by Rohit


when do you expect to release "SyntaxEditor vNext" 2019.1 ?

Posted 24 days ago by Actipro Software Support - Cleveland, OH, USA

While we can't offer a date at this time, we are probably within the last 10% of development of the UWP vNext version.  Please watch our blog for updates.

Actipro Software Support

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