When attempting to add a Control Event Handler to a control on a dialog, we are encountering the message: Add/Remove operation is impossible, the code element 'Cxxx' is read only.
After an hour of trying to solve it my self, a quick Google search turned up the following solutions.
- Add random charters to the .h/.cpp file
- clean your solution
- Close all open windows and close the project.
- Delete .ncb and .suo files
- Open your project solution and rebuild
- Attempt to add your new control event handler.
This seemed to work for me with
Microsoft Visual studios 2009
Version 9.0.21022.8 RTM