1. Unit 14 Event Driven Programming
Level 3 Computing
Year 1
Lecturer: Julie Hodsdon

2. Last time Introduced the unit
Introduced VB.NET’s Integrated Development Environment (IDE)
Learnt features of event driven programming
Created a simple form
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

3. Unit Learning outcomes
Understand the features of event driven programming
Be able to use the tools and techniques of an event driven language
Be able to design event driven applications
Be able to implement event driven applications
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

4. Assessment
This unit is assessed by practical coursework designed around the criteria set by Edexcel.
Three items of practical work (see wiki to be confirmed)
Assignment 1 will be issued in October and is due before half term.
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

5. Event Driven
What does it mean?
control flow of event driven programs is largely driven by external events (Mouse click, button press, keyboard input)
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

6. Procedural Programming
What does it mean?
control flow is determined by the program structure (sequence, step by step)
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

7. Today…..
We will create:
A simple GUI (graphical user interface) calculator
A simple calculator using the console as our input /output device.
Examine the code of both
Evaluate the programs
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

8. Visual Studio 2015
Let’s have a look at the IDE we will be using throughout this unit.
On your computer, after you login, start Visual studio 2013 (vs2013).
Then follow my video on You Tube so that you can work at the pace that suits you.
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

9. Understanding the program
Events
Sub routines
Variables
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

10. Console based Calculator
How will the program flow?
Before we write the code, we need to design the application.
Our design –
What are the inputs.
What are the outputs.
What does the interface look like.
You need to cater for adding, subtracting, multiplication and division between two numbers.
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

11. Console based Calculator
Task 1.
In pairs – (use Microsoft word or Visio)
Design a calculator application which will run in a command window.
This should be in the form of a storyboard.
You have 10 minutes.
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

12. Time for a break?
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

13. Console based Calculator
In Visual Studio – create a new console project
There is an example on the wiki that you can use
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

14. Evaluation Which is better and why? (in your opinion)
Task 2 – write an evaluation on -
How does the console calculator compare to the GUI calculator?
In terms of coding,
User experience.
Which is better and why? (in your opinion)
You may want to use this as a start for Assignment 1 D1
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

15. And finally……

16. Most, if not all, GUI systems and toolkits are designed to be event driven, meaning that the main flow of your program is not sequential from beginning to end. If you've never done GUI programming, this is one of the trickiest paradigm shifts. — Robin Dunn, speaking on GUI programming at OSCON2004
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

17. Hollywood Principle: "Don't call us; we'll call you. "
Hollywood Principle: "Don't call us; we'll call you." ... You implement the interfaces, you get registered. You get called when the time is right. This requires a distinctly different way of thinking to that which is taught in introductory programming where the student dictates the flow of control. — Dafydd Rees,
The user dictates the flow of control
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming

18. Submit Task 1 and Task 2 to Moodle before next lesson
Use the naming convention for TurnitIn as shown on the WIKI
Enrolment code is:
event
BTEC Level 3 Year 1 - Unit 14 Event Driven lProgramming