This example demonstrates a simple application using a GUI with a single view.
Click on the following link to download the example: HelloWorldGUI.zip
Click: browse to view the example code.
This application consists of 4 classes:
Application
class derived from CEikApplication.
Document class
derived from CEikDocument.
AppUi class
derived from CEikAppUi.
AppView class
derived from CCoeControl.
E32Main() marks the entry point to the
example. It calls EikStart::RunApplication() to create
a new application instance. The UI framework then calls CExampleApplication::AppDllUid() to obtain the application's UID. The UID returned must match the
second value defined in the project definition file.
Once
the application is created, the UI framework calls CExampleApplication::CreateDocumentL() to create an instance of the document class. CreateDocumentL() 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.
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 CEikAppUi -derived class and this class takes
care of user interaction.
AppUI creation uses two phase construction
where first CExampleDocument::CreateAppUiL() is called
and then the framework calls the second phase constructor of the appUI
class. CExampleAppUi::ConstructL() creates and owns
the view. User commands are handled by the CExampleAppUi::HandleCommandL() method.
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.
The example contains a resource file HelloWorld.rss which defines resource information. This
includes a menubar with four menu items, an icon and caption.
HelloWorld.hrh defines the menu command
IDs and HelloWorld.pkg file is the source file
used for installation file (SIS file) generation.
Steps to build the example:
You can build the example from your IDE or the command line.
If you use
an IDE, import the bld.inf file of the example
into your IDE, and use the build command of the IDE.
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:
bldmake bldfiles
abld build
For the emulator,
the example builds an executable called helloworld.exe in the epoc32\release\winscw\<udeb or urel>\ folder.