<task id="GUID-EA107811-240C-5F95-922B-7C042FA00A87" xml:lang="en"><title>Reading a String Resource </title><abstract><p>The simplest use of a resource file involves reading

string resources and interpreting the source data. </p></abstract><prolog><metadata><keywords/></metadata></prolog><taskbody>

<context id="GUID-FD651A99-73F0-4CDD-9B4F-7C3A1DE8C4BE"><p>Resources are defined in terms of structs which are accessed

and read by the <xref href="GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA.dita"><apiname>RResourceFile</apiname></xref> class, and interpreted

by the <xref href="GUID-B375D32E-1F91-30FA-8605-A2E163111F9A.dita"><apiname>TResourceReader</apiname></xref>. An application may also

use resources from multiple files simultaneously. See <xref href="GUID-98903A01-CD04-5345-84AE-2E440CE06E11.dita">Resource File examples</xref> for more information. </p><p>Consider a sample resource file where

a struct of STRING is defined having a single member of type <codeph>LTEXT</codeph>: </p><codeblock xml:space="preserve">// define structures

<info>Compile the resource file using the resource compiler (rcomp)

to generate an <filepath>.rsc</filepath> file and an <filepath>.rsg</filepath> file. </info>

<info><p>For information on resource compiler, see <b>Symbian^3 Tools

Guide &gt; Building</b>. </p></info>

<info> <filepath>.rsc</filepath> file contains the resource data;

this is the resource file that must be referred to at run-time by

the <codeph>RResourceFile</codeph> class in the C++ code. </info>

<info> <filepath>.rsg</filepath> file is a <keyword>generated    

                 header</keyword> file that contains <codeph>#define</codeph> statements for each resource defined in the source file. In the

resource file generated here, the only resource is called <codeph>hello</codeph> and the generated header file contains: </info>

<info>Note that the name in the generated header file is converted

to upper case. </info>

<info> <codeph>#include</codeph> the <filepath>.rsg</filepath> file

in the file containing the C++ code, to access the resource IDs generated

by the resource compiler. For example, for a project refered as <codeph>ReadText</codeph>, this might be: </info>

<info>Initialize the <codeph>RResourceFile</codeph> object in the

C++ program, specifying the name of the resource file: </info>

<info>Note: To access the resource file contents, a session with the

file server must be started using an instance of <xref href="GUID-E263C747-946F-35AA-9F1D-41833BD350FC.dita"><apiname>RFs</apiname></xref> class. </info>

<info>Use one of the three functions (<xref href="GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA.dita#GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA/GUID-9B16E6B8-84A4-37DF-BBB4-EC8B04FDB14C"><apiname>RResourceFile::AllocReadLC()</apiname></xref>, <xref href="GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA.dita#GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA/GUID-8CEE29E0-78F3-3DD6-B068-85C8E0403884"><apiname>RResourceFile::AllocReadL()</apiname></xref> or <xref href="GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA.dita#GUID-AA6DEF11-6F23-3523-A9F7-F15DF918E1BA/GUID-DF6DFFD5-E923-3C4E-87F0-BC4EE7C8B586"><apiname>RResourceFile::ReadL()</apiname></xref> to read a resource as shown in the following code fragment: </info>

<info>Interpret the resource data using a <codeph>TResourceReader</codeph> object. This provides access to the text string through a pointer

descriptor as shown in the following code fragment: </info>

<result id="GUID-565451D8-6C9E-4F1C-BC15-BFA4F3DD6D1D"><p>In this example, once the resource data is no longer needed,

the heap descriptor, dataBuffer, can be removed from the cleanup stack

and destroyed as shown in the code fragment: </p><codeblock xml:space="preserve">CleanupStack::PopAndDestroy();</codeblock><p>When all operations on the resource file are complete, the resource

file can be closed using the RResourceFile::close() function as:  </p><codeblock xml:space="preserve">resourceFile.Close();</codeblock></result>

}</codeblock> <p>A <codeph>TPtrC</codeph> representing the second

item can be constructed using the <codeph>ReadTPtrC()</codeph> function.

The example simply takes the length of the text <codeph>Enter</codeph>: </p> <codeblock id="GUID-9817910D-0661-513D-BB3A-9557D70688AD" xml:space="preserve">// open the resource file