Thanks for finding it ( I'd searched this forum, but didn't know about that one ...too many similar forums ) I've experienced the case where a newly added control doesn't get added to designer.cs, and been able to resolve it simply by cutting / pasting the control. The error list shows the warning "Generation of designer file failed: The method or operation is not implemented." 3. Investigating the possible differences between these files reveals no significant configuration differences, other than actual asp:xxx controls implemented on each page.
If by any chance you have deleted your .and you wanted to regenerate it or you wanted to update the .file when you put new controls on your page.Solution 1 : Right Click on you aspx or ascx file and select "Convert to Web Application".As soon as you do this a new .file will be created for you with all the controls in it.Please Like and Share the Blog, if you find it interesting and helpful.) to an ascx or aspx file, visual studio is supposed to automatically add the definition for that control to the file (associated with that ascx or aspx).