1. CIS 115 Lecture 2

2.  Visual Studio 2005 Professional Edition (Requires Windows XP Pro)  MSDN Library for Visual Studio 2005 Available from MSDNAA

3.  A platform that allows the development and deployment of desktop and web applications  Allows user choice of many.NET languages  May program in One of them  May create different parts of application in different languages ▪ Visual Basic ▪ C# (C Sharp) ▪ C++ ▪ J++ ▪ Etc.

4.  Integrated Development Environment – allows the automation of many of the common programming tasks in one environment  Writing the code  Checking for Syntax (Language) errors  Compiling and Interpreting(Transferring to computer language)  Debugging (Fixing Run-time or Logic Errors)  Running the Application

5.  4th Generation Programming Environment / Development Language  Based on BASIC language  Beginners All-Purpose Symbolic Instructional Code  Most widely used tool for developing Windows Applications  Graphical User Interface (GUI)  Menus, Buttons, Icons to help the user  Full Object-Oriented Programming Language

7.  User creates a new project in Visual Studio  A solution and a folder are created at the same time with the same name as the project  The project belongs to the solution  Multiple projects can be included in a solution  Solution  Contains several folders that define an application’s structure  Solution files have a file suffix of.sln  Project: contains files for a part of the solution  Project file is used to create an executable application  A project file has a suffix of.vbproj  Every project has a type (Console, Windows, etc.)  Every project has an entry point: A Sub procedure named Main or a Form

8.  Solution folder  Solution file (.sln)  Project folder ▪ Project file (.vbproj) ▪ Visual Basic source files (.vb) ▪ My Project folder: contains configuration information common to all projects ▪ The file AssemblyInfo.vb contains assembly metadata ▪ The References folder contains references to other assemblies ▪ The bin folder contains the executable file produced as a result of compiling the application

10.  Select the “Create Project” option from the “Recent Projects” box on the Start Page

12.  This is a Visual Basic GUI object called a form  Forms are the windows and dialog boxes that display when a program runs.  A form is an object that contains other objects such as buttons, text boxes, and labels

13.  Form elements are objects called controls  This form has:  Two TextBox controls  Four Label controls  Two Button controls  The value displayed by a control is held in the text property of the control  Left button text property is Calculate Gross Pay  Buttons have methods attached to events

14. Design Window ToolboxToolbox Solution Explorer Properties Window

15.  Step 1: Add a Control to the Form – Button  Look in the Toolbox for the Button Control  Select the Button with the Mouse  Draw a Rectangle Region in the Design Window by holding the mouse button down  Release the mouse button to see your button  (Can also be added by double clicking on the button in the Toolbox)

17.  Add a Second Button to the Form  Put it in the lower right corner  The project now contains  a form with 2 button  controls

18.  Properties  All controls have properties  Each property has a value (or values)  Determine the Look and Feel (and sometimes behavior) of a Control  Set initially through the Properties Window  Properties Set for this Application  Name  Text

19.  The name property establishes a means for the program to refer to that control  Controls are assigned relatively meaningless names when created  Change these names to something more meaningful  Control names must start with a letter  Remaining characters may be letters, digits, or underscore

20. btnCalcGrossPaybtnClose txtHoursWorked txtPayRate lblGrossPay Label1 Label2 Label3  The label controls use the default names (Label1, etc.)  Text boxes, buttons, and the Gross Pay label play an active role in the program and have been changed

21.  Should be meaningful  1st 3 lowercase letters indicate the type of control  txt…for Text Boxes  lbl…for Labels  btn…for Buttons  After that, capitalize the first letter of each word  txtHoursWorked is clearer than txthoursworked  Change the name property  Set the name of button1 to btnWelcome  Set the name of button2 to btnExit

22.  Click on the Control in the Design Window  Select the appropriate property in the Properties Window

23.  Determines the visible text on the control  Change the text property  bntWelcome  set to “Say Welcome”  btnExit  set to “Exit”  Do not need to include the “ “ in your text field  Notice how the buttons now display the new text

24.  The GUI environment is event-driven  An event is an action that takes place within a program  Clicking a button (a Click event)  Keying in a TextBox (a TextChanged event)  Visual Basic controls are capable of detecting many, many events  A program can respond to an event if the programmer writes an event procedure

25.  An Event Procedure is a block of code that executes only when particular event occurs  Writing an Event Procedure  Create the event procedure stub ▪ Double click on control from Design Window – for default event for that control OR ▪ Open the Code Editor (F7 or View Menu/Code option) ▪ Select Control & Select Event from drop down windows in Code Editor  Add the event code to the event procedure stub

28.  Select the btnWelcome control from the Form Controls List Box

29.  Select the Click event from the list of many available events  Buttons have 57 possible events they can respond to

30.  Beginning of Procedure is created for you  If you create stub by double clicking on control it will create a stub for the most commonly used event for that control

31.  Write the code that you want executed when the user clicks on the btnWelcome button  Type: MsgBox (“Welcome to Visual Basic”)  Must be contained within the Event Procedure Stub

32.  Not Case Sensitive  Visual Basic will “correct” case issues for you  Keywords are in Blue  Special reserved words  Comments in Green  Problems with Syntax (Language) will be underlined in blue

33.  Rules  Use spaces to separate the words and operators  Indentation and capitalization have no effect  Recommendations  Use indentation and extra spaces for alignment  Use blank lines before and after groups of related statements  Code all variable declarations at the start of the procedure  Group related declarations

34.  Usage  Type an apostrophe ( ' ) followed by the comment  The compiler ignores everything on the line after ‘  Used for documentation/readability and to disable chosen statements during testing  Recommendations  Follow apostrophe with a star for readability ( ‘* )  Use at beginning of program to indicate author, purpose, date, etc.  Use for groups of related statements and portions of code that are difficult to understand

35. Code that follows recomendations '* ====================================== '* Class: CIS 115-101 '* Author: Paul Overstreet '* Purpose: Homework 1 – VB Application '* Date: 11/30/01 '* ====================================== Public Class Form1 Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventAr… '*Variable declarations Dim dOrderTotal As Decimal Dim dDiscountAmount As Decimal '*Get total from textbox dOrderTotal = txtOrderTotal.Text '*Calculate the proper discount dDiscountAmount = dOrderTotal * 0.25 ' dDiscountAmount = dOrderTotal * 0.25 End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)… ‘*Code goes here End Sub End Class

36.  Create an Event Procedure for when the btnExit button is clicked  Have it display “Goodbye” in a MsgBox  Then “End” – this will terminate the program

37.  You can switch between the Design Window and the Code Window (once opened) by clicking on the tabs at the top of the  Design and Code Windows  Form1.vb(Design) is the  design window  Form1.vb is the Code Window

38.  Click the Run Icon on the Standard Toolbar  Or Press F5  This will begin the program  Display the Form/Window  Nothing will happen  Waiting on an Event

39.  Click on the “Say Welcome” button  The message box should display  Click on the “Exit” button  The message box should display  The application should terminate

40.  Make sure to save your work  SAVE ALL (not Save Form)  Visual Basic applications are  made of several files -  Often even several forms

41.  Lab Handout  Intro to VB Controls and Properties  See handout for details and due date  Questions?