Styles CSS 2010v1 to 2025v2 399 in ASP.NET WebForms

Styles CSS 2010v1 to 2025v2 399 in ASP.NET WebForms

Posted by: enrique.pv-ext on 30 July 2026, 10:41 am EST

• 

  enrique.pv-ext

  • Post Options:
  • Link
    Copy

  Posted 30 July 2026, 10:41 am EST - Updated 30 July 2026, 11:01 am EST

  Hi,
  
  Migrate from 2010v1 to 2025v2 399 in ASP.NET WebForms NET Framework 4.8.1.
  
  Using Controls from C1.Web.Wijmo.Controls.48.dll

  LEGACY

  

  875×927 73.6 KB

  

  2101×779 135 KB

  

  1444×912 95.4 KB

  

  960×978 83.4 KB

  

  1279×883 85.6 KB

  

  1054×858 71.3 KB

  new Wijmo

  

  932×849 70.3 KB

  

  1009×620 45.2 KB

  

  1639×877 139 KB

  

  974×797 62.2 KB

  

  928×830 65 KB

  

  952×837 69.5 KB

  any suggestions or approach to use LEGACY css / styles to apply new controls ??
  
  classes changed…

• 

  uttkarsh.matiyal

  

  • Post Options:
  • Link
    Copy

  Posted 31 July 2026, 3:03 am EST

  Hello Enrique,

  Apologies for the inconvenience. Unfortunately, the legacy Themes/CSS cannot be used with the latest version because the client-side HTML structure, CSS class names, and overall architecture have changed significantly between the versions.

  The recommended approach is to use the themes and styling provided with the latest version, as they are designed to work with the updated HTML and CSS structure.

  see: Theming | Getting Started with ASP.NET Web Forms

  Regards,
  
  Uttkarsh.

• 

  enrique.pv-ext

  • Post Options:
  • Link
    Copy

  Posted 3 August 2026, 10:39 am EST

  give me more ideas or samples about it ?

  change CSS for legacy to new ?
  
  Control 2010 to Control 2025
  
  CSS legacy → CSS new

  Matrix mapping legacy vs new CSS, maybe get html + css render in old pages (Playwright, Selenium,
  
  Screenshot automation…)
  
  Create legacy-look.css ??

• 

  uttkarsh.matiyal

  

  • Post Options:
  • Link
    Copy

  Posted 3 August 2026, 11:31 pm EST

  Hello Enrique,

  I understand the migration effort involved, and I wish I had a simpler answer. However, we’re not able to provide a complete legacy-to-new CSS/class mapping or a ready-made ‘legacy-look.css’ for a few reasons:

  1. C1 WebForms is now a legacy product in maintenance mode, with no active feature development. We continue to address bugs and critical issues, but we’re not adding new features or enhancements. As a result, creating and maintaining a separate legacy-look theme is not something we’re able to provide.
  2. The HTML structure has changed, not just the class names. The new Wijmo-based controls use different DOM structures and CSS architecture, so a class-to-class mapping wouldn’t reliably reproduce the legacy look.
  3. The rendering varies by control and state (hover, selected, disabled, etc.), making a single mapping incomplete and potentially misleading.

  Instead, I’d recommend using the built-in themes in the current version as the baseline (as shared in my earlier reply).

  If there are specific visual differences that affect usability or functionality, please share the control and some screenshots. We can then help identify the closest CSS classes/variables available in the new version.

  I understand this may not be the complete solution you were hoping for, but we’re happy to help with specific control-by-control questions during the migration.

  Regards,
  
  Uttkarsh.