An Introduction to Visual Basic .NET and Program Design Chapter 1 An Introduction to Visual Basic .NET and Program Design

Introduction A program is a step-by-step series of instructions Programming is the process of writing these instructions Programmers, or software developers, design and write programs An application is a collection of one or more programs designed to complete a specified task Program development is the process of writing applications

What is Microsoft Visual Basic .NET? VB.NET is a programming environment that allows you to build programs for the Windows operating system or any system that supports Microsoft’s .NET architecture VB.NET is based on the Visual Basic programming language Evolved from BASIC (Beginner’s All-purpose Symbolic Instruction Code The process of writing a program using a programming language is called coding.

Programming and Application Development Machine Cycle – how a computer processes information -- 4 Steps! Fetch – get line of code Decode – convert from programming language to machine language (Binary) Execute – execute the instructions Store – store the results – repeat cycle

Application Types Windows Applications

Application Types Web Applications

Application Types Console Applications

Application Types Windows Services

Application Types Web Services

Application Types Components

The Development Cycle

Phase 1 – Analyze Requirements Verify the requirements are complete Make the initial determination that it is possible to solve the problem using a program List input and output data required Determine whether the input data is available for testing Ensure that the information provided explains how to convert the input data into output data so that a solution, or algorithm, can be developed

Phase 2 – Design Solution Develop a logical model that illustrates the sequence of steps you will take to solve the problem Objects are smaller pieces of a program Object model – illustrates the attributes and methods of an object. Attributes -- values that determine, for example, the appearance of an object. Methods -- instructions that the object uses to perform actions or generate outputs.

Phase 2 – Design Solution Object Model

Phase 2 – Design Solution Flowcharts graphically represent the logic used to develop an algorithm Control structures, included in flowcharts, allow the programmer to specify the code that will execute only if a condition is met Pseudocode expresses the step-by-step instructions using keywords and depicts logical groupings or structures using indentation

Control Structures

Pseudocode

Storyboard

Phase 3 – Validate Design Validate, or check, the program design Step through the solution with test data Compare the program design with the original requirements

Phase 4 – Implement Design Write the code that translates the design into a program Create the user interface Create comments, or notes, within the code that explains the purpose of the code Test the code as it is written THIS IS WHERE IT GETS FUN! You tried to write a program … does it work? Does it do what you wanted it to do? Is it user-friendly?

Phase 4 – Implement Design

Phase 5 – Test Solution Test plan Make sure to set boundary values Test cases Make sure to set boundary values

Phase 6 – Document Solution Includes the requirements documents, program design documents, user interface documents, and documentation of the code Code should be archived electronically

Object-Oriented Programming and Object-Oriented Design Data and the code that operates on the data are packaged into a single unit called an object Object-oriented design Represents the logical plan of a program as a set of interactions among objects and operations

Rapid Application Development

Chapter 1 Complete