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<concept id="GUID-2B7F7484-3A44-4A96-9B5D-79DF8A09115A" xml:lang="en"><title>How resource files work</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>In the Symbian platform, <xref href="GUID-5F749184-C804-41FC-BA81-038783BDC967.dita">resource</xref> files

are used to define UI components used in applications. See <xref href="GUID-0FB60233-993A-4BF2-9E8C-E03AD092359B.dita">Managing resource

files</xref> for information on defining the data structure.</p>

<p>The following resource files are typically used as source files

in Symbian applications:</p>

<ul>

<li><p><codeph>.rss</codeph> – resource source files used

for UI components in the application. For more information, see <xref href="GUID-EC49B54F-7724-433B-BD7F-201DE3B7DAA6.dita">Resource file structure</xref>, <xref href="GUID-23A60DE7-B72D-41BD-9F1E-882D31A7E3C7.dita">Required resource file statements</xref>, and <xref href="GUID-2C74E932-B1CA-434B-AF96-66D52D689620.dita">Optional resource file statements</xref>.</p>

</li>

<li><p><codeph>_reg.rss</codeph> – resource source file

used for registration. For more information, see <xref href="GUID-BF1AAA0D-DF2F-4E1D-A0D2-F419BD32F97A.dita">Creating registration resource files</xref>.</p>

</li>

<li><p><codeph>.hrh</codeph> – resource header file used

to define enumerated sets of values. For more information, see <xref href="GUID-D52E98C3-F5EE-4CE1-A4F5-2EF41A066B8A.dita">Creating resource header files</xref>.</p>

</li>

<li><p><codeph>.rls</codeph> – localization files used as

a source for UI texts strings in applications, and for managing these

texts. For more information, see <xref href="GUID-E111C4E8-1342-4E87-ACB4-5B630AF1501C.dita">Internationalization

and localization</xref>.</p>

</li>

</ul>

<p>The structures and symbolic IDs of the files are used in various

ways in your code.</p>

<p> The resource files above are then compiled to yield the following

files:</p>

<ul>

<li><p><codeph>.rsc</codeph> or <parmname>rNN</parmname>, where NN is a two number Symbian locale ID - compiled, machine-readable

resource files used by the application.</p></li>

<li><p><codeph>.rsg</codeph> - generated resource header

file containing the symbolic IDs of the resources for inclusion into

your code.</p></li>

<li><p><codeph> _reg.rsc</codeph> or <parmname>_reg.rNN</parmname>, where NN is a two number Symbian locale ID - compiled, machine-readable

resource file used for registration .</p></li>

</ul>

<p>The <parmname>rsc</parmname>, <parmname>rNN</parmname>, and <parmname>_reg.rsc</parmname> files

need to be included in your <parmname>.sis</parmname> installation

file so that they are placed in the device when the application is

installed.</p>

<p>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 <parmname>.rsc</parmname>.</p>