The file extension ASCX identifies ASP.Net user controls. It is reusable code that can be accessed in ASP.Net web pages. Ascx files are simple text files that can contain ASP.Net code as well as functions in .Net languages like C # and Visual Basic.
Alternatively, a C # or Visual Basic file is referenced in an ASCX file, which provides the functionalities, while the ASCX file contains only the ASP.Net code for the web page elements. The referenced files usually have a double ending like ascx.Cs or ascx.Vb.
By default, the .Net framework also provides ASCX files, such as a user login or an input field, which can be used with Visual Studio, for example.
Please note that for newer versions of Adobe Dreamweaver the extension 'ASPNet_Support.Mxp' found in the Dreamweaver program folder under 'configurationDisabledFeatures' has to be installed first.
Most often resolving problems with opening ASCX files is very simple. Just install an appropriate program that supports such files. All of the listed programs support ASCX files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of ASCX files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate ASCX files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Dreamweaver applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Dreamweaver has been installed.
Sometimes problems with opening ASCX files may not lie with the application itself, but can arise due to other causes, such as: