Purpose

The purpose of this tutorial is to demonstrate how a simple program is created using NS Basic/Symbian OS. You should have NS Basic/Symbian OS installed before beginning this tutorial.

Description of the Program

The program to be developed will display a form with a button on it. When the user taps the button, the program responds with the message

 "Hello--Welcome to NS Basic/Symbian OS"

Program Development

1. Startup

• Start NS Basic/Symbian OS from the Start menu.
• At the initial screen select New Project

2. Modify Project Properties

• Change the (Name) to "HelloPgm".

3. Modify Form Properties

• You should now see a blank screen with the title "Form1"
• Select the form in the Project Explorer by clicking on it.
• In Properties, change (Name) to "Hello"

4. Add a button to the form

• Select button ("OK") in the Toolbox by left clicking on it
• Move the cursor to the desired location within the Design Screen
• Click the left mouse button to place the button object on the screen

Change the button's text:

• Click on the new button in the Design Screen
• In the Properties window, change Label to Tap Here

Resize the button:

• Select the button by left clicking on it
• Position the mouse cursor to any resize marker around the button
• Depress the left mouse button and drag the object to a different size
• Release the left mouse button to stop the action

Relocate the button on the screen:

• Select the button by left clicking on it
• Position the mouse cursor to the middle of the button
• Depress the left mouse button and drag the object to some other screen location
• Release the left mouse button to stop the action

5. Add commands to be executed when the button is tapped

• Double click on the button
• A code window will appear with some code statements already supplied for you
• Position the cursor to the line below the SUB statement
• Enter the following command

  MsgBox "Hello -- Welcome to NS Basic/Symbian OS"

• Close the code window.

6. Save the Project

• Select "File" from the top main menu
• Select "Save project" and save your program as HelloPgm
• This will save your project in the directory c:\NSBasic\Projects under the name HelloPgm.prj
• All form definitions, form objects, all code, and other project info are saved into the one project file.

7. Generate the Downloadable App

• Select "Run" from the main menu.
• Select "Compile HelloPgm" from the dropdown menu.

If you have any errors, an error message will appear and the code window will appear with the section of code where the error occurred highlighted. Errors must be corrected and Compile repeated until there are no more errors. If you do not have errors, a message box will appear showing the size of the compiled application.

• If you corrected any errors, you should re-save the project.
• This action creates an installer called HelloPgm.sisx in folder c:\nsbasic\Download.
• The next step will be to download it to your device.

Congratulations !! You have now written your first NS Basic/Symbian OS program.

Testing The Project

First, make sure your device is connected to your computer using the Nokia PC Suite or equivilent.

• Go into c:\nsbasic\downloads
• Double click on HelloPgb.sisx.
• Install as you would any other application.
• If you get "Certificate Error. Contact the Application Supplier", do the following:
  1. On the device, go to Tools
  2. App. Manager
  3. Highlight App. downllds.
  4. Click "Options"
  5. Select "Settings"
  6. Software installation: change from "Signed only" to "All"
• Run the app on the device

Extending the Tutorial

Let's explore some further features of NS Basic/Symbian OS. We'll do this by modifying your first program to be more complicated.

Exit NS Basic/Symbian OS by choosing File and Exit from the menu.

Restart

• Restart NS Basic/Symbian from the Start menu.
• The first screen will list recent projects you have worked on, so that you may easily pick one for modification.

• Select the HelloPgm project by clicking on it.
• The project will load into the IDE and show you the project as you last left it.

Revision: Change the message

• Double click on the button to bring up the code window.
• Enter the following code after the SUB statement

	Dim s as string
	Dim d as date
	d=today()
	s=str(d)

• Change the MsgBox statement to be

	MsgBox "Today is " + s 

• Close the code window.
• Compile.
• Test by compiling and downloading as done earlier in the tutorial.
• When you run, the message displayed should be

  Today is yy/mm/dd

  where today's date replaces yy/mm/dd

Revision: Add code at program startup

• From the menu, select Project...Startup Code
• After the Sub line, enter this command:

	msgbox "HelloPgm will continue when you tap on OK"

• Close the code window.

This code will be executed when the program starts execution. The program displays the message and waits until the user taps on the OK button

• Compile the program. If error free, test it on your device.

Revision: Code at Form display time

This change will add a field which shows the time-of-day. Another button will be added to cause the time to be updated with the latest time.

Add a field to the form to be used to display the time of day

• Select the field object from the Toolbox by clicking on it. The field object looks like "T".
• Move the cursor to the desired screen location and left click to place the field object.
• Select the object by left clicking on it.
• In the Properties Window, change the field's Name to "fldTime"
• Resize the object as needed.

Add code to fill in the time-of-day when the form displays

• Right click on the form name in the Project Explorer
• Select "View After Code"
• Enter the following code after the SUB line

	dim wk as string
	dim t as time
	t = now()
	wk = str(t)
	fldTime.text = wk

• Close the code window.

This code will set the time of day into the field object "fldTime" just after the device displays the form to the user. The statement

	t = now() 

gets the current time and stores it in the time variable "t". The str function converts the internal time format into a text string of the format hh:mm:ss which is the used to store into the field object for display.

The above code could be compressed into one statement as

	fldTime.text=str(now()) 

Add a button to redraw the form so that the latest time appears

• Select the button object in the toolbox
• Place it on the Design Screen with a left click
• Select the object
• In the Properties Winddow, enter "Redraw the screen" as the button's Label.
• Resize object as needed.

Add code to the button to cause the redraw

• Double click on the button
• Enter the following statement after the SUB line

	Redraw 

• Close the code window
• This will cause the entire screen to be redrawn. This will trigger the code supplied for the form that is executed before the form objects are redrawn. This code fills in the latest time to the form's field object for display.
• Compile and when error free, test on your device.