Skill Area 336 Explain Essential Programming Concept. Programming Language 2 (PL2)

Transcription

1 Skill Area 336 Explain Essential Programming Concept Programming Language 2 (PL2)

2 336.2-Apply Basic Program Development Techniques Identify language components for program development Use IDE to create an application Write code to execute tasks Run and debug a program

3 The Visual Studio IDE Visual Studio is an integrated development environment, often abbreviated as IDE Provides everything needed to create, test, and debug software including: The Visual Basic language Form design tools to create the user interface Debugging tools to help find and correct programming errors Visual Studio supports other languages beside Visual Basic such as C++ and C#

4 Visual Studio 2008 (continued) Application: program or suite of programs Windows-based application: Has a Windows user interface Runs on a desktop computer User interface: what the user sees and interacts with when using an application Web-based application: Has a Web user interface Runs on a server Accessed with a computer browser

5 Solutions, Projects, and Files Solution: a container that stores projects and files for an entire application Project: a container that stores files associated with a specific piece of the solution A solution may contain one or more projects

6 Solutions, Projects, and Files (continued) Figure 1-1: Illustration of a solution, project, and file

7 Starting Microsoft Visual Studio 2008 Figure 1-2: How to start Microsoft Visual Studio 2008

8 Figure 1-3: Visual Studio 2008 Professional Edition startup screen

9 Creating a Visual Basic 2008 Windows-Based Application Figure 1-4: How to create a Visual Basic 2008 Windows-based application

10 Figure 1-5: Completed New Project dialog box

11 Figure 1-6: Solution and Visual Basic Project created by Visual Studio 2008

12 Managing the Windows in the IDE Figure 1-7: How to manage the windows in the IDE

13 The Windows Form Designer Window Windows Form Designer window: Allows you to create (design) the GUI Graphical user interface (GUI): What the user sees and interacts with when using the application Windows Form object (or form): Adds other objects such as buttons and text boxes to the form to create the GUI Has a title bar with caption and Minimize, Maximize, and Close buttons Tab at top of designer windows has [Designer]

14 Figure 1-8: Windows Form Designer window

15 The Solution Explorer Window Solution Explorer window: Displays a list of projects contained in this solution Displays the items contained in each project Figure 1-9: Solution Explorer window

16 The Solution Explorer Window (continued) Source file: a file containing program instructions Code: program instructions Form file: a file containing code associated with a Windows form Give each form file a meaningful name using the Properties window

17 The Properties Window Properties: a set of attributes that determine an object s appearance and behavior Properties window: displays properties of selected object Default property values are assigned when an object is created

18 The Properties Window (continued) Figure 1-10: Properties window showing the properties of the Form1.vb file

19 The Properties Window (continued) Properties window includes an Object box and a Properties list Object box: Located immediately below Properties window title bar Contains the name of the selected object Properties list: Left column displays names of properties Use the Alphabetical or Categorized buttons to sort the display of properties Settings box: Right column containing the current value of each property

20 Properties of a Windows Form Figure 1-11: Windows form properties listed in the Properties window

21 Properties of a Windows Form (continued) Class definition: block of code that defines the attributes and behaviors of an object All class definitions are contained in namespaces Namespace: defines a group of related classes Dot member access operator: the period that separates words in an object s name to indicate a hierarchy of namespaces Name property: used to refer to an object in code Give each object a meaningful name Hungarian notation: naming convention using three or more character prefix to represent the object type

22 Properties of a Windows Form (continued) Pascal case: First letter of each word in the name is uppercase First part of name is object s purpose Second part of name is object s class Text property: controls the caption displayed on form s title bar StartPosition property: determines the form s position on the screen when application starts Font: general shape of characters in text Recommended font is Seqoe UI font Point: a measure of font sizes; one point = 1/72 inch

23 The Toolbox Window Toolbox: Contains objects that can be added to other objects, such as a form Each tool has an icon and a name to identify it Each tool represents an object, called a control Controls: Objects displayed on a form Represented as icons in the toolbox Can be locked in place on the form

24 The Toolbox Window (continued) Figure 1-12: Toolbox window

25 The Toolbox Window (continued) Figure 1-13: How to add a control to a form

26 The Toolbox Window (continued) Figure 1-14: How to manipulate the controls on a form

27 The Label Control Label control: Displays text that user cannot edit Used as prompts to explain controls or display output Name should end with Label Control names use camel case Camel casing: lowercase first word; uppercase first letter of each subsequent word in the name Not necessary to assign meaningful names for labels used as prompts because they are never used in code Labels used for output should have meaningful names

28 The Label Control (continued) Figure 1-15: Wizard application s user interface

29 The Button Control Button control: Performs an immediate action when clicked Its name should end with Button Text property: specifies the text that appears on the button s face

30 The Picture Box Control Picture box control: used to display an image on a form Image property: specifies the image to display SizeMode property: handles how the image will be displayed Settings: Normal, StretchImage, AutoSize, CenterImage, or Zoom

31 The Code Editor Window Events: user actions while program is running Examples: clicking, double-clicking, scrolling Event procedure: set of instructions to be executed when an event occurs Tells the object how to respond to an event Code editor: used to enter programming code

32 The Code Editor Window (continued) Figure 1-16: How to open the Code Editor window

33 The Code Editor Window (continued) Figure 1-17: Code Editor window opened in the IDE

34 The Code Editor Window (continued) Class statement: used to define a class Begins with Public Class <class name> Ends with End Class Class Name list box: lists the names of objects (controls) included in the user interface Method Name list box: lists the events to which the selected object is capable of responding When you select a control from the Class Name list box and a method name, a code template for the event appears in the Code Editor window Syntax: rules of the language

35 The Code Editor Window (continued) Keyword: a word with special meaning in a programming language Event code template has a procedure header and procedure footer Sub procedure: block of code that performs a task Event s procedure header: Begins with keywords Private Sub Procedure name includes object name and event name Handles clause indicates for which objects events this code will execute

36 The Me.Close() Instruction Me.Close() instruction: closes the current form at run time If the current form is the main form, the application is terminated Me keyword: refers to the current form Method: predefined VB procedure that can be invoked (called) when needed Sequential processing: each line is executed in sequence Also called a sequence structure

37 The Me.Close() Instruction (continued) Figure 1-19: Me.Close() instruction in the Click event procedure

38 Saving a Solution An asterisk appears on the designer and Code Editor tabs if a change was made since the last time the solution was saved Figure 1-20: How to save a solution

39 Starting and Ending an Application Startup form: the form to be displayed when the application starts Figure 1-21: How to specify the startup form

40 Starting and Ending an Application (continued) Figure 1-22: Project Designer window

41 Starting and Ending an Application (continued) Figure 1-23: How to start an application

42 Starting and Ending an Application (continued) Figure 1-24: Result of starting the Wizard application

43 Starting and Ending an Application (continued) When you start a VB application, the IDE creates an executable file Executable file: Can be run outside of Visual Studio 2008 Has a file extension of.exe Stored in the project s bin\debug folder

44 Starting and Ending an Application (continued) Figure 1-25: How to end an application

45 Using an Assignment Statement Properties window is used to set property values at design time Assignment statement: assigns a value to a variable or property of a control Used to set property values at run time String: zero or more characters enclosed in quotation marks Assignment operator: the = symbol

46 Using an Assignment Statement (continued) Figure 1-26: Assignment statements entered in the Code Editor window

47 Printing Your Application Figure 1-27: How to print an application s code and user interface

48 Closing the Current Solution Closing a solution closes all projects and files in that solution You are prompted to save any files that have unsaved changes Figure 1-28: How to close a solution

49 Opening an Existing Solution Only one solution can be open at any one time If a solution is already open, opening a different one will close the currently open solution

50 Opening an Existing Solution (continued) Figure 1-29: How to open an existing solution

51 Programming Tutorial Figure 1-46: Result of starting the Wizard application

52 Programming Example Figure 1-54: User interface