cis 115 lecture 2. visual studio 2005 professional edition (requires windows xp pro) msdn library...
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CIS 115 Lecture 2
Visual Studio 2005 Professional Edition(Requires Windows XP Pro)
MSDN Library for Visual Studio 2005
Available from MSDNAA
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.
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
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
Solution
.NET FrameworkVisual Studio .NET
Project
CommonLanguageRuntime
IntegratedDevelopmentEnvironment
Source files
Visual Basiccompiler
1 2 3
Assembly
Intermediate Language (IL)
Class references
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
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
Select the “Create Project” option from the “Recent Projects” box on the Start Page
This is a Visual BasicGUI 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
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
Design WindowT
oolbox
SolutionExplorer
PropertiesWindow
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)
Add a Second Button to the FormPut it in the lower right corner
The project now contains a form with 2 button controls
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
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
btnCalcGrossPay btnClose
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
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
Click on the Control in the Design Window
Select the appropriate property in the Properties Window
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
The GUI environment is event-drivenAn 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
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
Select the btnWelcome control from the Form Controls List Box
Select the Click event from the list of many available events
Buttons have 57 possible events they can respond to
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
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
Not Case Sensitive Visual Basic will “correct” case issues for
youKeywords are in Blue
Special reserved wordsComments in GreenProblems with Syntax (Language)
will be underlined in blue
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
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
'* ======================================'* 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
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
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
Click the Run Icon on the Standard Toolbar
Or Press F5
This will begin the programDisplay the Form/WindowNothing will happen
Waiting on an Event
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
Make sure to save your work SAVE ALL (not Save Form) Visual Basic applications are made of several files - Often even several forms
Lab Handout Intro to VB Controls and Properties See handout for details and due date Questions?