How resource files work

In the Symbian platform, resource files are used to define UI components used in applications. See Managing resource files for information on defining the data structure.

The following resource files are typically used as source files in Symbian applications:

• .rss – resource source files used for UI components in the application. For more information, see Resource file structure, Required resource file statements, and Optional resource file statements.

• _reg.rss – resource source file used for registration. For more information, see Creating registration resource files.

• .hrh – resource header file used to define enumerated sets of values. For more information, see Creating resource header files.

• .rls – localization files used as a source for UI texts strings in applications, and for managing these texts. For more information, see Internationalization and localization.

The structures and symbolic IDs of the files are used in various ways in your code.

The resource files above are then compiled to yield the following files:

• .rsc or rNN, where NN is a two number Symbian locale ID - compiled, machine-readable resource files used by the application.

• .rsg - generated resource header file containing the symbolic IDs of the resources for inclusion into your code.

• _reg.rsc or _reg.rNN, where NN is a two number Symbian locale ID - compiled, machine-readable resource file used for registration .

The rsc, rNN, and _reg.rsc files need to be included in your .sis installation file so that they are placed in the device when the application is installed.

When the application framework launches an application, it loads the application resource file. The application framework compares the system locale language setting with the available resource files, and loads the resource file whose extension matches the locale language code. If there is no match, then the system loads the resource file with the .rsc.