1. Import the required classes and interfaces.

   import net.rim.device.api.ui.UiApplication;
   import net.rim.device.api.ui.container.MainScreen;

2. Create the class that represents your application. Extend the UiApplication class to create an application that has a UI.

   public class MyApplication extends UiApplication
   {

3. Implement main() in your application class. This method represents the primary entry point for your application.

       public static void main(String[] args)
       {

4. In main(), create an instance of your application class.

           MyApplication myApp = new MyApplication();

5. Invoke enterEventDispatcher() to start the event thread and allow your application to process events.

           myApp.enterEventDispatcher();
       }

6. Implement the constructor for your application class.

       public MyApplication()
       {

7. In the application constructor, invoke pushScreen() to push an instance of your application's first screen on to the display stack.

           pushScreen(new MyApplicationScreen());
       }    
   }

8. Create the class that represents your application's first screen. Extend the MainScreen class to create a screen that consists of a title section, separator element, and main scrollable section.

   class MyApplicationScreen extends MainScreen
   {

9. Implement the constructor for your screen class.

       public MyApplicationScreen()
       {

10. In the screen constructor, perform any initial tasks to set up your screen. For example, to set a title for your screen, invoke setTitle().

            setTitle("My First BlackBerry Device Application");
        }
    }

Code sample: Creating the framework for applications with a UI

import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.container.MainScreen;

public class MyApplication extends UiApplication
{
    public static void main(String[] args)
    {
    	   MyApplication myApp = new MyApplication();       
        myApp.enterEventDispatcher();
    }
    
    public MyApplication()
    {
        pushScreen(new MyApplicationScreen());
    }    
}

class MyApplicationScreen extends MainScreen
{
    public MyApplicationScreen()
    {            
        setTitle("My First BlackBerry Device Application");
    }
}