CSCI 3328 Object Oriented CSCI 3328 Object Oriented Programming in C# Programming in C#

Chapter 1: Introduction to C#Chapter 1: Introduction to C#

Xiang Lian

The University of Texas Rio Grande Valley

Edinburg, TX 78539

xiang.lian@utrgv.edu

1

Objectives

• In this chapter, you will– Know requirements of this course

– Recall basic components in a computer system

– Learn the evolution of programming language

– Refresh your memory about the object-oriented programming

– Become aware of the .Net Framework for Visual C#

2

Background Required

• C++ Programming– If you made an A in 1370/1170 you will do fine

with some effort

– If you have already taken 2380, you will find this course not very difficult

• You need to be able to look up how to get things done (for example, look up syntax)

3

Programming, Programming, Programming

• This class is unlike other courses in that you will spend a lot of time doing actual programming

• You should never copy a program from someone else• Even if your program does not perform as good as

someone else’s, you should submit what you have

• You should not hesitate to ask questions in class

4

Assignments

• Unless I announce it, programs are due in one week after assignment is given in class, or posted • Occasionally, I will give two weeks for difficult

programs

• You should work on a program the same day it is assigned• That way you can ask questions during the

following class period

5

Use of the Textbook

• I will not be covering chapter by chapter

• I will cover important points needed to complete the assignments

• You need to search the index in the back to find the topic needed for each assignment

• You can also obtain help from MSDN at the Microsoft site

6

Versions of Visual C#

• You can program using VC# 2008, 2010, or 2012

• Our book only covers 2008 – If you use 2010 or 2012, you may need to find

help from other sources or the Web

– Usually, there are not many differences for programming with a higher version of Visual C#

7

The Time for Class

8

• I expect to hold the class for little over an hour each time

• Remaining time should be spend with your assigned groups to discuss the project in class

• Please do not exchange programs with each other, just ideas

9

CSCI 1380: Elements of a Computer System

• Hardware– CPU

–Main memory

– Secondary storage

– Input / Output devices

• Software– System programs

– Application programs (e.g. Visual Studio)

10

Programming Languages

• Machine language

• Assembly language

• High-level language– E.g., C#

11

Object Technology

• We humans are very good in recognizing and working with objects, such as a pen, a dog, or a human being

• We learned to categorize them in such a way that make sense to us. –We may categorize them as animate object,

inanimate objects, pets, friends, etc.

12

Object Technology (cont'd)

• We some times classify objects based on their attributes, for example, green apples or red apples, fat or slim people, etc.

• If you think about it each object has many attributes. – If I ask you list the attributes of an orange, you

probably could list many things such as color, shape, weight, smell, etc.

13

Object Technology (cont'd)

• In addition to attributes, all objects exhibit behaviors.

• A dog eats, barks, wags its tail, plays, and begs. – A dog exhibits many more other behaviors than

this short list.

• Another thing we need to remember about objects is that objects interact between each other

14

Object Technology in Visual C#

• Visual C#– Object-oriented • E.g. forms, labels, buttons, radios, checkboxes, etc.

– Properties of objects• E.g. background color of forms

– Event-driven• Behaviors events of objects

• E.g. clicks

15

.Net Framework

• A software platform• Language-neutral• Designed for cross-language compatibility– Applications written in C# may reference a DLL

file written in any other language

• 2 components:– Common Language Runtime (CLR)– Class Libraries

16

The .Net Framework

• Underneath the applications you develop using C# is the .Net Framework containing a library of classes needed for windows forms and web forms.

• The .Net framework interacts with the Common Language Runtime (CLR), which in turn interacts with the operating system and the hardware

• This way programs you write using C# can run on different operating systems and hardware platforms as long as it has the correct version of the .Net installed on it

17

Common Language Runtime

• Execution Engine of .Net• Manages the execution of programs and

provides core services:– Code compilation–Memory allocation– Thread management– Garbage collection

18

Class Libraries

• Designed to integrate with the common language runtime

• This library gives the program access to runtime environment

• The class library consists of lots of prewritten code that all the applications created in VC# .Net and Visual Studio .Net will use

• The code in Visual C # for all the elements like forms, and controls actually comes from the class library

19

Namespaces

• Within the .Net Framework, related classes are grouped into Namespaces

• You need to insert a “using AppropriateNamespace” in your program

• After that you can refer to methods and attributes of classes contained therein

20

To Get .Net Namespace Documentation

• Visit:http://msdn.microsoft.com/en-us/library/ms229335.aspx

21

How Do You Write and Run a Program?

• Use the Visual Studio to create a project• File New Project…• The project file will have the extension *.csproj. The project stores all

related files, including the source file you write. Every project has a solution file with the extension *.sln. You would be opening this file when you want to return to your program you were writing. This will open all associated files. The associated files may be contained in a subdirectory.

• After writing the source code, go to Build and build your solution, which creates the intermediate code

• Go to Debug and start without debugging• The program run will finish and give you a prompt to press any key to

continue. Starting with debugging, it will complete the run and return to you to the IDE. If your IDE does offer “without debugging”, add a Console.ReadKey() statement.

22

Options for a New Project

• Console application

• Windows forms application

• …

23

Hello Programusing System;//using System.Collections.Generic;//using System.Linq;//using System.Text;

namespace sayHello{ class sayHello { static void Main(string[] args) {

Console.WriteLine("Hello!"); Console.WriteLine("Welcome to Dr. Lian's C# Class!"); Console.ReadLine();

} }} 24

Using the Form Designer

• You can size the form by holding the handles in the corners or the middle

• Controls and other items are added to the form using the toolbox• The control or item has properties that can be set

• To write the code for an event, you can click on the view code button above the solution explorer or by simply clicking on a button or anything else on the form

• Files with code you write will have extension .cs• Files ending with designer.cs are code files generated by

Visual Studio

25

Naming Controls and Boxes

• Use a convention you will remember• You can start all button names with btn• An accept button will be named btnAccept• An exit button will be named btnExit

• All text boxes will start with txt • Sales amount will be named txtSalesAmount

• All labels with start with lbl• lblEnterName

• It is up to you to choose naming conventions you will recognize

26

Your First Assignment

• Assignment #1

• The purpose of this assignment is to practice reading and writing to console using C#. It is a simple assignment. Use the following program run to design and write your program. Please submit Program listing and a screen capture of the program run. Follow the textbook examples to add comments as documentation.

27

Assignment Submission

• Make sure to include your name, assignment number, date due and date completed on each assignment you submit

• Assignment should be submitted in a manila folder with your name and assignment number appearing on the tab

• Submit your assignments to the Blackboard

28

Exercises

• Give a brief explanation of the .NET framework

• What is the Common Language Runtime?

• How do you place “Total Square Feet: 1238” in a text box? Assume that 1238 in an integer stored in a variable called sqFt.

29