1. Introduction to Programming and Visual C# 2008
Chapter 1
Introduction to Programming and Visual C# 2008

2. Chapter Objectives - 1
Describe the process of visual program design and development
Explain the term object-oriented programming
Explain the concepts of classes, objects, properties, methods, and events
List and describe the three steps for writing a C# program
Describe the various files that make up a C# project

3. Chapter Objectives - 2
Identify the elements in the Visual Studio environment
Define design time, run time, and debug time
Write, run, save, print, and modify your first C# program
Identify syntax errors, run-time errors, and logic errors
Look up C# topics in Help

4. Writing Windows Applications
Your C# programs will look and act like standard Windows programs
Use tools to create:
Labels
Text boxes
Buttons
Radio buttons
Picture box
Check box
Menu Bar
Drop-down list
List box
Group box

5. Windows Graphical User Interface (GUI)
Windows GUI defines how elements look and function
Windows are called forms
Elements are called controls
Add controls to your forms using the toolbox
C# projects follow the object-oriented programming (OOP) technique
GUI is pronounced "gooey".

6. Programming Languages— Procedural and Object Oriented
Procedural — Basic, C, Cobol, Fortran, PL/1, Pascal
Program specifies exact sequence of operations
Object Oriented Programming (OOP) — C#, Java, Visual Basic
User controls the sequence
User actions cause events to occur which trigger methods
A method is a set of programming statements written by the programmer.

7. The Object Model Objects have properties, methods and events
An object is based on a class
Objects (noun or thing)
Forms, Controls
Properties (adjectives)
Name, Color, Size, Location
Methods (verbs)
Close, Show, Clear
Events (occurs when user takes action)
Click, KeyPress, Scroll, Close window
Classes (template or blueprint)
Contain definition of all available properties, methods and events
OOP terminology is used throughout the text.
Chapter 12 presents object-oriented programming in greater depth.

8. OOP Terminology Object.Property Object.Method SalesForm.Text
BillingForm.Show
exitButton.Show
SalesForm.Text is pronounced “sales form dot text”.
The term members is used to refer to both properties and methods.

9. Object Model Analogy Class = automobile
Object = one individual automobile
Object is an instance of the automobile class
Properties = make, model, color, engine, number of doors
Methods = start, speedup, slowdown, stop
Events = arrive, crash
An example of the color property would be yourAuto.Color = Blue
An example a method would be yourAuto.Start
An example of an event would be yourAuto.Crash

10. Microsoft’s Visual Studio 2008
.NET 3.5 Framework
Environment that allows objects from different languages to operate together, standardizes references to data and objects
.NET languages all compile (translate) to Microsoft Intermediate Language (MSIL)
MSIL runs in the Common Language Runtime (CLR)
Programming Languages
Visual C#, Visual C++, Visual Basic
C# Versions
Express Edition, Standard Edition, Professional Edition, Team System
Team System is available as four specialized versions for large enterprise application development.
Professional or Team System Database versions should be used if advanced features of database management are needed.
The trial version packaged with this textbook is the 180-day trial version of the Professional Edition.
Express edition of C# is available for free download from
The text is based on the Professional Edition.

11. Writing C# Programs – The Three-Step Process (Planning)
Design the user interface
Sketch screens
Show forms and all controls
Name forms and objects on form
Consult with user
Plan the properties
Plan the C# code
Plan classes and methods
Write pseudocode
Actual C# code must follow the language syntax rules. Pseudocode is an English expression or comment that describes the action. For example, an event that occurs when the user clicks the Exit button would be written in Pseudocode as End the project or Quit.

12. Writing C# Programs – The Three-Step Process (Programming)
Define user interface
Create forms and controls
Set the properties
Name each object and define its attributes
Write the code
Define the actions of the program
Setting the properties of an object could include the contents of a label, the size of the text, the words that appear on a button or in the form’s title bar.

13. C# Application Files Solution file Project file Form files
A C# application is called a solution and can consist of one or more projects
.sln extension
Project file
Describes project and lists files included
.csproj extension
Form files
.cs, .Designer.cs, .resx extensions
The Visual Studio environment creates several more files
The solution (.sln) file is a file that holds information about the solution and the projects it contains.
The project (.csproj) file describes the project and lists files that are included in the project.
The .cs (C#) file holds the code methods that are written.
The Designer.cs (C#) file is created by the Form Designer and holds the definition of the form and its controls.
The resource file (.resx) is a text file that defines all the resources used by the form.
The additional files created by the Visual Studio environment are:
The solution user options (.suo) file stores information about the state of the IDE.
The project user options (.csproj.user) file is a text file that holds IDE option settings.
The Program.cs (C#) file contains automatically generated code that runs first when your application is executed.

14. The Visual Studio Environment
Integrated development environment (IDE)
Includes various tools
Form designer
Editor for entering and modifying C# code
Compiler
Debugger
Object Browser
Help
Form designer allows you to visually create a form.
The compiler translates the C# statements into intermediate machine code.
The debugger helps to locate and correct errors.
The object browser allows you to view the available classes, objects, properties, methods and events.

15. Default Environment Settings
Visual Studio 2008 allows selection of default IDE profile
Available with full version of Visual Studio
Choose Visual C# Development Settings
Text uses the Visual C# settings
Settings can be saved for more than one language
To switch between the settings for languages:
Select Tools/Import and Export Settings
Choose Reset all settings
The first time you open the Visual Studio IDE, you must select the default environment settings for Visual C# development.

16. The New Project Dialog Select File/New Project
New Project Dialog Box Opens
Select the Windows Forms Application template
Deselect the check box for Create directory for solution, which creates an extra level of folders that are not needed for single-project solutions.
If a Start Page opens, without an open project, you can close the Start Page by clicking on its Close button. (See Figure 1.4 in textbook)
Select Visual C# Windows
Enter the Project Name

17. The IDE Main Window
Solution Explorer
Toolbox
Properties window
Windows can be displayed or hidden from the View menu.
The Visual Studio environment has a main window and various child windows.
Main Document window
Each window can be moved, resized, closed, or customized

18. The Toolbars Toolbar buttons are shortcuts
Each button’s command is also a menu selection
Select View/Toolbars to display or hide a toolbar
Three commonly used toolbars
Standard
Layout
Text Editor

19. Document Window Use tabs to switch between open documents
Items in Document window
Form Designer
Code Editor
Project Designer
Database Designer
Object Browser
Close any document window using its Close button.
Use Ctrl + Tab to switch to another open document in the Document window.

20. The Form Designer Design forms for user interface
Change size of form using sizing handles or selection border
A new default form is added when a new C# application is started

21. The Solution Explorer and Properties Windows
Solution Explorer window
Holds filenames for project files
Lists classes referenced
Holds name of solution (.sln) file
Properties Window
Used to set properties for objects in project
Sort properties in the properties window alphabetically or by category using the buttons on the Properties window.

22. Toolbox Holds tools to place controls on form
Tools vary depending on edition of C#
Sort tools in the toolbox by right-clicking on the toolbox and selecting Sort Items Alphabetically from the shortcut menu.

23. Help Help with specific tasks Selected Topic Help Search Filter
Help displays in a new window, independent of the Visual Studio IDE window. This allows you to have Help and the Document window open at the same time.
Help Index
Help Contents
Help Favorites
Index Results

24. Design Time, Run Time, Debug Time
Design user interface (forms)
Write code
Run Time
Testing project
Running project
Debug Time
Run-time errors
Pause program execution
The IDE window title bar displays (Running) or (Debugging) to indicate that a project is no longer in design time.

25. Writing Your First C# Project - 1
Run Visual Studio
Start a New Project
Select File/New/Project
Visual C# and Windows must be selected for Project types
Select Windows Forms Application for the template
Enter Hello World as the project name
Click the OK button
If you are using Visual Studio Professional and this is the first time VS has been opened for this user, you need to select Visual C# Development Settings from the Choose Default Environment Settings dialog box (see Figure 1.3 in textbook).

26. Writing Your First C# Project - 2
Windows and Windows Forms Application have been selected and “HelloWorld” has been entered in the Name textbox.

27. Writing Your First C# Project - 3
Set Up Your Environment
Click Window/Reset Window Layout, Click Yes
Point to toolbox icon
Pushpin icon toggles Auto Hide feature for toolbox
Optional
Tools/Options
Options dialog box
Startup under Environment
At startup list
Show empty environment
After Clicking Yes when choosing Window/Reset Window Layout the IDE will match Figure 1.12 in the textbook.
Clicking the pushpin icon pins the toolbox window open rather than allowing it to Auto Hide.
You can show the Start Page at any time by selecting View/Start Page.

28. Writing Your First C# Project - 4
Plan the project
Design the user interface
Plan the properties
Plan the code
(Planning the properties and code have been done for the first sample project)
Draw the sketch by hand and label the form and controls with the names you plan to give them.

29. Writing Your First C# Project - 5
Define the User Interface
Set Up the Form
Drag handle to resize form
Place Controls on the Form
Double-click the Label tool

30. Writing Your First C# Project - 6
Draw a button on the form
Click the button tool and draw with the crosshair pointer
Create a second button
Double-click the Button tool in the toolbox
Use snap lines to align all three controls
Snap lines appear as you draw or move controls on the form and can help to align the controls.
Click outside of a control to deselect it.

31. Writing Your First C# Project - 7
Controls
Select, Delete, Move or Resize
Select a control
Click on it
Delete a selected control
Select control and press the Delete key
Move a selected control
Point inside control (not on a handle) and drag to a new location
Resize a selected control
Point to a resizing handle and drag to resize

32. Writing Your First C# Project - 8
Set Properties
Press F4 key if Properties window is not displayed
Click title bar of Properties window to make active window
Click on control to change its properties
Click Alphabetical button to sort properties
Select Name property
Enter Name for Control (used in code)
Select AutoSize property
Choose True or False
Select Text property
Change value for display on form
Don’t confuse the Name property with the Text property. The Name property refers to the control in C# code. The Text property determines what the user will see on the form. C# sets both properties to the same value by default, it is easy to confuse them.

33. Writing Your First C# Project - 9
Lock the Controls
When controls are in desired location, lock them in place
Unlock controls by clicking again on Lock Controls on the context menu
Right-click on the form and select Lock Controls
Right-click to access the context menu, select Lock Controls.
The Lock Controls menu item works like a toggle switch to lock and unlock controls.
Context menus differ depending on the current operation and system setup.
A button that is selected and locked

34. Writing Your First C# Project - 10
Set Button Properties
button1
Name - displayButton
Text - Display
button2
Name – exitButton
Text – Exit
Always set the Name property of controls before writing code. This allows the method names to match the control names, saving confusion.

35. Writing Your First C# Project - 11
Change Properties of the Form
Text property appears in the form’s title bar
Set StartPosition property to CenterScreen
Icon indicates that the form’s controls are locked
The next slide describes changing the form’s name and file name.
Form’s Text property appears in the title bar

36. Changing a Form’s Name
You must change the name of the form’s file and the name of the class
If you change the filename first, the IDE automatically changes the name of the class
The reverse is not true
See the next slide for a picture of the Properties window for the form.

37. HelloForm.cs Name of the form’s file File name Name of the form class
If you change the name of the form’s class in the properties window, you also must manually change the name of the file.
It is much better to change the name of the file and allow the IDE to rename the form’s class to match.

38. Write Code
C# Events
While a project is running the user can perform actions, each of which causes an event to occur
C# will execute a method when code has been written for an event
C# ignores events for which no methods are written
Some events, like clicking on a button, you care about. Some events, like moving the mouse and resizing the window, you do not care about.

39. C# Event Handlers Write C# code in methods
Each begins with the words private void
Code in method is enclosed in braces { }
C# names the event-handling method as the object name, an underscore (_) and the name of the event
displayButton_Click
Event-handling methods are also called event handlers.

40. C# Code Statements Comment statements Ending a statement
Sometimes called remarks
Ending a statement
Code statements are terminated by a semicolon (;)
Assignment statements
Executing a Method
Methods always have parentheses
Use this keyword to execute method of the current form
Examples of methods are:
helloButton.Hide();
messageLabel.Show();

41. The Comment Statement
Comments or remarks are for project documentation
Explain purpose of the program
Provide identifying information
Non-executable statements within the code
Automatically colored green by the editor
Single-line comments begin with two slashes
// Display a message to the user.
Multiline comments begin with /* and end with */
/* First line
...
Last line */

42. Ending a Statement Most C# statements end with a semicolon (;)
A statement can appear on multiple lines
The semicolon determines the end of the statement
Comments and a few other C# statements do not end with a semicolon
A later chapter will discuss the C# statements that do not end with a semicolon.

43. The Assignment Statement
Assigns a value to a property or variable
Operates from right to left
The value on the right side of the equal sign is assigned to the property on the left side of the equal sign
Enclose text (a literal) in quotation marks (" ")
Chapter 3 discusses variables.
Do not enclose a numeric value in quotation marks.
Do not use quotation marks around the terms true and false which are special key terms in C#.
messageLabel.Text = "Hello World";

44. Ending a Program by Executing a Method
To execute a method of an object, write:
Object.Method();
Methods are always followed by parentheses
Can help distinguish methods from properties
To execute a method of the current form use the this keyword
this.Close();
this.Close() is used to end a program in the event-handling method for an Exit button or menu choice
Properties never have parentheses.
The keyword this refers to the current object.
It can be omitted since a method without an object reference defaults to the current object.

45. Code Event-Handling Methods - 1
Double-click the Display button
The Editor window opens
The header line for the method is in place
The insertion point appears inside the opening and closing braces
private void displayButton_Click(object sender, EventArgs e) { | }

46. Code Event-Handling Methods - 2
Editor tab
Form Designer tab
Comment statement
Assignment statement
Allow the Editor and IntelliSense to help. If IntelliSense does not pop up, likely the name of the control is misspelled.
An asterisk on the tab at the top of the window indicates there are unsaved changes.
Execute the Close method to end the program

47. Run the Project - 1 Use one of three techniques to run
IDE Title bar indicates program is in run time
Use one of three techniques to run
Open the Debug menu / Start Debugging
Press the Start Debugging toolbar button
Press F5, the keyboard shortcut
Form for the running application
Editor and Form Designer locked tabs

48. Run the Project - 2 Click the Display button
“Hello World” message appears in the label
Click the Exit button to end the project and return to Design time

49. Save Your Work File menu/Save All
Saves the current form, project and solution files
Click Save All toolbar button to quickly save all files
File menu/Close Solution
If file has not been saved since last change, prompt to save appears
By default Visual Studio saves files automatically to a temporary location each time you compile or run the project.
NOTE: Do not try to save a modified version of a project by giving the project a new name. See Appendix C on how to move or rename a project.

50. Open the Project Three ways to open a project File menu/Open Project
Browse to find .sln file (small “9” as part of file’s icon)
Choose project from File/Recent Projects menu
Start Page (if available)
View/Other Windows/Start Page

51. Modify the Project
Modify the project by making changes to the design (including properties) and/or the code (including comments)
Double-click on a button to open the editor
Editor will open in corresponding click event code
Change the Font property of the form and this will set the default Font for all objects on the form.
Comments – Always begin each method with comments that tell the purpose of the method.
Properties button
Click to expand Font list
Settings box

52. Print the Code Print View Event Handlers Open Editor window File/Print
Select a button control
Click Events button (lightning bolt) on Properties window
Double-click on the event name
Code Editor window opens inside template for event handler
The Print command is disabled unless code is displayed and the window is selected.

53. Automatically Generated Code
Using Statements
Provide references to classes from the language library
System.Windows.Forms
Allows program to refer to all Windows controls
Namespace Statement
.NET Framework requires every program component to have a namespace
Class Statement
A new class can inherit from another class
Without the using statement, the complete reference would have to be used for each control.
Using System.Windows.Forms allows messageLabel to be used in code. Without the using statement the same label would have to be referred to as System.Windows.Forms.Label.messageLabel.
Classes will be discussed in detail later in the textbook.

54. Finding and Fixing Errors
Syntax errors
Breaking the rules of the language
Editor finds most, compiler reports remainder
Editor identifies syntax errors with a red squiggly line
Run-time errors or exceptions
Program halts due to statements that cannot execute
For example, impossible arithmetic operations
Logic errors
Program runs but produces incorrect results
Carefully proof output to make sure it is correct
Computations, text and spacing
Language rules include punctuation, format and spelling.
Jump to an error line by double-clicking on it in the Error List window.
In Chapter 3 there is information on how to catch exceptions so that the program does not halt when an error occurs.

55. Project Debugging Program errors are bugs
Editor highlights syntax and run-time errors
Programmer must locate logic errors
C# allows edit-and-continue
Fix error and press F5 or Debug/Continue
Clean Compile
No errors during the compile process
If you get the message, “There were build errors. Continue?” click No. Yes allows the last cleanly compiled version to run rather than the current version.

56. Modifying an Event Handler -1
Deleting an Event Handler
Select form or control
Click Events button in Properties window
Select and delete name of the method
Select the event
Delete the method name

57. Modifying an Event Handler - 2
Renaming a Control
Change the name of the control in the design window
Switch to Editor window
Right-click name of event-handling method
Select Refractor/Rename
Enter new name in Rename dialog box
Click Apply in Preview Changes dialog box
Refractor changes all references to the old name to the new name including the line in the Designer.cs file that assigns the event handler.

58. Naming Rules and Conventions for Objects
Follow C# rules for naming objects, methods and variables
Good programmers follow naming rules and conventions
Most programming shops have standards that must be followed
When programmers consistently follow standards, programs are easier to read and to maintain, by both the original programmer and by others
You should have a set of naming standards and always follow them.

59. The Naming Rules Name must begin with a letter or an underscore
Name can contain letters, digits, and underscores
Name cannot include a space, punctuation mark or be a reserved word
Names are case sensitive
exitbutton, ExitButton and exitButton refer to three different objects
Reserve words include Close or button. A name can contain a reserve word as part of a longer name. For example, exitButton and closeButton are legal.

60. The Naming Conventions -1
Follow standard naming conventions
Use camel casing
Begin name with lowercase character
Capitalize each additional word in name
Use meaningful names, indicate purpose of object
Append full name of control’s class
Examples
messageLabel, exitButton, discountRateLabel

61. The Naming Conventions - 2
Do not keep C# default names
Exception is labels that never change during execution
Use pascal casing to name forms and classes
Capitalize first letter of name and first letter of all other words in name
Examples
HelloForm, MainForm, AboutForm

62. Visual Studio Help Installing and Running MSDN Viewing Help Topics
Can be run from a hard drive or online
Viewing Help Topics
Help window opens on top of IDE window
Filter by C# and either Express or Professional Edition
Context-Sensitive Help
Select a C# object (i.e. form or control)
Place insertion point in a word in the editor
Press F1
A good way to start using Help is to view the topics that demonstrate how to look up topics in Help.
Display context-sensitive Help about the environment by clicking in an area of the screen and pressing Shift + F1.