BuildAction property indicates what Visual Studio does with a file when a build is executed.
BuildAction can have one of several values:
Content The file is not compiled, but is included in the Content output group.
Eg: this setting is the default value for an .htm or other kind of Web file.
Compile The file is compiled into the build output. This setting is used for code files.
None The file is not included in the project output group and is not compiled in the build process.
Eg: is a text file that contains documentation, such as a Readme file.
Embedded Resource This file is embedded in the main project build output as a DLL or executable.
It is typically used for resource files.
Eg:
Note: Set Build Action property to 'Compile' to reference the namespace of the cs file in App_Code folder. For futher information, see here.
