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<reference id="GUID-F64B88E0-49DA-5563-896E-29BAB8A244C9" xml:lang="en"><title>HelloWorld: A simple GUI application with a single view</title><shortdesc>This example demonstrates a simple application using a

GUI with a single view. </shortdesc><prolog><metadata><keywords/></metadata></prolog><refbody>

<section id="GUID-8B4671BB-1A8E-4782-BDF5-19F98EDBD1E3"><title>Download</title> <p>Click on the following link to

download the example: <xref href="guid-6013a680-57f9-415b-8851-c4fa63356636/zips/guid-a2004cb9-da88-4ec7-a85e-dd648022f4f9.zip" scope="external">HelloWorldGUI.zip</xref></p><p>Click: <xref href="guid-6013a680-57f9-415b-8851-c4fa63356636/guid-a2004cb9-da88-4ec7-a85e-dd648022f4f9.html" scope="peer">browse</xref> to view the example code. </p> </section>

<section id="GUID-B52E7C31-DDA5-4570-9D95-A18CFFD0E1F8"><title>Class Summary</title><p><xref href="GUID-E36E2F07-09E7-32BC-BB83-14DF9232E7D9.dita"><apiname>CEikApplication</apiname></xref></p><p><xref href="GUID-B33A8A56-D1BE-3E3D-B5AC-F644A5C764DB.dita"><apiname>CEikDocument</apiname></xref></p><p><xref href="GUID-1185F595-0488-3E93-8D60-6B3A1A3AC32E.dita"><apiname>CEikAppUi</apiname></xref></p><p><xref href="GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160.dita"><apiname>CCoeControl</apiname></xref></p></section>

<section id="GUID-EAF6161A-0C6A-4397-A24F-19365ABFEC34"><title>Design and implementation</title> <p>This application

consists of 4 classes: </p> <ul>

<li id="GUID-28A83A4A-D743-556B-88EB-D65AAFD29D19"><p>Application

class derived from <xref href="GUID-E36E2F07-09E7-32BC-BB83-14DF9232E7D9.dita"><apiname>CEikApplication</apiname></xref>. </p> </li>

<li id="GUID-EF3F2195-1D04-56A4-B439-C2B50F543F74"><p>Document class

derived from <xref href="GUID-B33A8A56-D1BE-3E3D-B5AC-F644A5C764DB.dita"><apiname>CEikDocument</apiname></xref>. </p> </li>

<li id="GUID-65ABFCB1-BC5A-5BCA-9F45-D5FF82AB1AE4"><p>AppUi class

derived from <xref href="GUID-1185F595-0488-3E93-8D60-6B3A1A3AC32E.dita"><apiname>CEikAppUi</apiname></xref>. </p> </li>

<li id="GUID-12BE51BC-0F68-5C5E-A279-4AE00E96FC7D"><p>AppView class

derived from <xref href="GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160.dita"><apiname>CCoeControl</apiname></xref>. </p> </li>

</ul> <p> <codeph>E32Main()</codeph> marks the entry point to the

example. It calls <codeph>EikStart::RunApplication()</codeph> to create

a new application instance. The UI framework then calls <codeph>CExampleApplication::AppDllUid()</codeph> to obtain the application's UID. The UID returned must match the

second value defined in the project definition file. </p> <p>Once

the application is created, the UI framework calls <codeph>CExampleApplication::CreateDocumentL()</codeph> to create an instance of the document class. <codeph>CreateDocumentL()</codeph> internally calls the constructor of the document class and passes

the supplied reference to the constructor initialisation list. The

document has no real work to do in this simple GUI application. </p> <p>As soon as the document has been created the UI framework creates

an instance of the application UI (appUI). The appUI class is an instance

of a <xref href="GUID-1185F595-0488-3E93-8D60-6B3A1A3AC32E.dita"><apiname>CEikAppUi</apiname></xref> -derived class and this class takes

care of user interaction. </p> <p>AppUI creation uses two phase construction

where first <codeph>CExampleDocument::CreateAppUiL()</codeph> is called

and then the framework calls the second phase constructor of the appUI

class. <codeph>CExampleAppUi::ConstructL()</codeph> creates and owns

the view. User commands are handled by the <codeph>CExampleAppUi::HandleCommandL()</codeph> method. </p> <p>The app view class is used to draw the view. The

view in this example consists of a simple outline rectangle with text

drawn in the middle. </p> <p>The example contains a resource file <filepath>HelloWorld.rss</filepath> which defines resource information. This

includes a menubar with four menu items, an icon and caption. </p> <p> <filepath>HelloWorld.hrh</filepath> defines the menu command

IDs and <filepath>HelloWorld.pkg</filepath> file is the source file

used for installation file (SIS file) generation. </p> </section>

<section id="GUID-8EBC5AE8-45DD-4AD1-BA3B-3F013F351646"><title>Building and configuring</title> <p>Steps to build

the example: </p> <ul>

<li id="GUID-81019373-E4C4-545E-85B9-1C4810203D5D"><p>You can build

the example from your IDE or the command line. </p> <p>If you use

an IDE, import the <filepath>bld.inf</filepath> file of the example

into your IDE, and use the build command of the IDE. </p> <p>If you

use the command line, open a command prompt, and set the current directory

to the source code directory of the example. You can then build the

example with the SBSv1 build tools with the following commands: </p> <p><userinput>bldmake bldfiles</userinput> </p> <p><userinput>abld

build</userinput> </p> </li>

<li id="GUID-83E08D73-33DB-520B-8606-6547796EDE28"><p>For the emulator,

the example builds an executable called <filepath>helloworld.exe</filepath> in the <filepath>epoc32\release\winscw\&lt;udeb or urel&gt;\</filepath> folder. </p> </li>

</ul> </section>