OVERVIEW:
Creating a new VB.NET project:
New project created from the NEW PROJECT window:
BUILD MENU:
DEBUG MENU:
HELLO WORLD
DATA TYPES AND VARIABLES
BOOLEAN TYPES
Numeric types: Integrals, Floating Point, Decimal
The Select case statement
Loops
SERIAL COMMUNICATION
Setting Up
VB.Net is a simple, modern, object-oriented computer programming language developed by Microsoft to combine
the power of .NET Framework and the common language runtime with the
productivity benefits that are the hallmark of Visual Basic.
Visual
Basic .NET (VB.NET) is an object-oriented computer programming language
implemented on the .NET Framework. Although it is an evolution of classic
Visual Basic language, it is not backwards-compatible with VB6, and any code
written in the old version does not compile under VB.NET.
The following
reasons make VB.NET a widely used professional language:
- Modern, general-purpose programming language.
- Object oriented.
- Component oriented.
- Easy to learn.
- Structured language.
- It produces efficient programs.
- It can be compiled on a variety of computer platforms.
- Part of .Net Framework.
GETTING STARTED:
Creating a new VB.NET project:
Once Visual Studio is running the first step is to create a
new project. Do this by selecting New
Project from the File menu. This will cause the New Project window to appear containing a range of
different types of project. For the purposes of this tutorial we will be
developing a Windows Forms
Application so make sure that
this option is selected.
CREATING NEW PROJECT:
· The first thing you do when you want to create a new application is to create a NEW PROJECT.
This can be done from
start page.
New project created from the NEW PROJECT window:
Then the “NEW PROJECT” window will
appear.
In this window you will select an
appropriate template based on what kind of application you want to create, and
a name and location for your project and solution.
The most common applications are:
- · Windows form application.
- · Console application.
- · WPF application
- · ASP.NET web application.
- · Silverlight application.
Select WINDOWS FORMS APPLICATION.
TOOLBOX
When you select WINDOWS FORM
APPLICATION, you will get FORM DESIGN WINDOW,it is used to design USER
interface by making use of TOOLBOX on the left side of window,
The TOOLBOX contains all the
necessary controls, etc. You need to create a user interface by making use of
these controls as shown in figure below.
In order to use these controls, just drag and drop it on to
your Design forms, as shown in figure.
Figure shows TOOLBOX
and DESIGN FORM:
The following screenshot shows, making use of these toolbox
controls for designing the user interface on DESIGN FORM.
PROPERTIES WINDOW
Each TOOLBOX we have used on our form has many properties
that we can set. This is done by using Properties window. We can find the
property window on the right bottom side of your project
BUILD AND DEBUGGING TOOL
The
visual studio has lots of Build and Debugging Tools,
BUILD MENU:
Below we see the Build menu. The most used Build tool is BUILD SOLUTIONS.
DEBUG MENU:
In
order to RUN or DEBUG your windows form we make use of DEBUG TOOLs. The most
used debug tool is START DEBUGGING. it can be find the shortcut for this on the
top of your visual studio windows.
Windows programming
When
creating ordinary windows form application, we can select between the
following:
- Windows form Application
- WPF application
HELLO WORLD
We
start by creating traditional “HELLO WORLD” application using Windows Form
Application is shown below. The visual studio UI shown below.
In this application we make use of simple textbox and
Button(Button name is changed to Submit in the properties) when we click on
submit the “HELLO WORLD ”massage will be displayed in the Textbox.
The OUTPUT of this
form as shown below:
The code is as follow:
Imports System.Text
Imports System
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
TextBox1.Text = "HELLO WORLD"
End Sub
End Class
DATA TYPES AND VARIABLES
“Variables” are simply storage
locations for data. You can place data into them and retrieve their contents as
part of a VB.NET expression. The interpretation of the data in a variable is
controlled through “Types”.
The VB.NET simple types consist of:
-
Boolean type
-
Numeric types: Integrals, Decimal
-
String type
BOOLEAN TYPES
Boolean types are declared using the keyword “Boolean”. They have two values:
“true” or “false”. In other languages, such as C and C++, boolean conditions
can be satisfied where 0 means false and anything else means true. However, in VB.NET
the only values that satisfy a boolean condition is true and false, which are
official keywords.
Example:
Dim Content as Boolean
Content=True
Numeric types: Integrals, Floating Point, Decimal
Example:
Dim I As Integer
I=35
Dim x As Decimal
X=10.5
Dim d As Double
String type
Control Flow
The if Statement
Dim d As Double
d=10000
String type
Example:
Dim abc As String
abc=”Hai..”
Special characters
that may be used in strings:
Arrays
Example:
Dim A(100) As Integer
A(0)=40
A(1)=10
A(2)=20
A(3)=30
Control Flow
To be able to control the flow in your
program is important in every programming language.
The two most important techniques are:
-
The if
Statement
-
The switch
Statement
The if Statement
The if statement is probably the most used mechanism to control the
flow in your application. An if statement allows you to take different paths of
logic, depending on a given condition. When the condition evaluates to a
Boolean true, a block of code for that true condition will execute. You have
the option of a single if statement, multiple else if statements, and an
optional else statement.
Example:
myTest=false
if myTest=false
Then
MsgBox ("Hello”)
End If
OUTPUT:
For more complex logic we use the if … else statement.
Example:
Dim myTest As Boolean
myTest=true
if myTest=false Then
MsgBox ("Hello1")
else
MsgBox
("Hello2")
End If
Or you can use nested if… else if sentences.
Example:
Dim
myTest As Integer
myTest=2
if myTest =1 Then
MsgBox ("Hello1")
elseif myTest = 2
Then
MsgBox ("Hello2")
else
MsgBox ("Hello3")
End If
The Select case statement
Another
form of selection statement is the select case statement, which executes
a set of logic depending on the value of a given parameter. The types of the
values a select statement operates on can be booleans, enums, integral types,
and strings.
Example:
Dim number As Integer = 8
Select Case number
Case 1 To 5
MsgBox("Between 1 and 5, inclusive")
' The following is the only Case clause that evaluates to
True.
Case 6, 7, 8
MsgBox ("Between 6 and 8, inclusive")
Case 9 To 10
MsgBox ("Equal to 9 or 10")
Case Else
MsgBox ("Not between 1 and 10, inclusive")
End Select
Loops
In VB.NET we have different kind of loops:
-
The while loop
-
The do loop
-
The for
loop
-
The foreach
loop
The while Loop
A while loop will
check a condition and then continues to execute a block of code as long as the
condition evaluates to a boolean value of true.
Example:
Dim
myInt As Integer = 0
While
myInt < 10
MsgBox("Inside Loop: " &
myInt.ToString())
myInt += 1
End
While
MsgBox("Outside
Loop: " & myInt.ToString())
Output
The do Loop
A do loop
is similar to the while loop, except that it checks its condition at the end of
the loop. This means that the do loop is guaranteed to execute at least one
time. On the other hand, a while loop evaluates its boolean expression at the
beginning and there is generally no guarantee that the statements inside the
loop will be executed, unless you program the code to explicitly do so.
Example:
Dim myInt As Integer = 0
Do
MsgBox("Inside Loop:
" & myInt.ToString())
myInt += 1
Loop While myInt < 10
MsgBox("Outside Loop:
" & myInt.ToString())
The for Loop
A for loop works
like a while loop, except that the syntax of the for loop includes
initialization and condition modification. for loops are appropriate when you
know exactly how many times you want to perform the statements within the loop.
Example:
For i As Integer = 0 To 9
MsgBox("Inside Loop: " & myInt.ToString())
myInt += 1
Next
MsgBox("Outside Loop: " & myInt.ToString())
OUTPUT:
The for each Loop
A foreach
loop is used to iterate through the items in a list. It operates on arrays or collections.
Example:
Dim names As String() = {"Elvis", "Beatles",
"Eagles", "Rolling Stones"}
For Each person As String In names
MsgBox(person)
Next
SERIAL COMMUNICATION
In telecommunication and computer
science, serial communication is the process of sending data one bit at a time,
sequentially, over a communication channel or computer bus. This is in contrast
to parallel communication, where several bits are sent as a whole, on a link
with several parallel channels.
Setting Up
Imports System.Data.SqlClient
Imports System.Net.Sockets
Imports System.Text
Shown in the above form before communicating with the particular
hardware device we should add SerialPort tool from the Toolbox.
This is standard Windows Forms Application via File
menu. To this add the button (name Ports) and a Rich Text Box.The button is
called btnGetSerialPorts and
the Rich Text called as rtbIncomingData (the name will become apparent
later).The rich text box is used as it is more flexible than the ordinary text
box. Its uses for sorting and aligning text are considerably more than the
straight textbox.
This shows all the devices
that appear as com ports, a mistake to make is thinking that a device if
plugged into the USB will appear as a COM Port.
The baud rate is the
amount of possible events that can happen in a second. It is displays usually
as a number of bit per second, the possible number that can be used are 300,
600, 1200, 2400, 9600, 14400, 19200, 38400, 57600, and 115200 (these come from
the UAR 8250 chip is used, if a 16650 the additional rates of 230400, 460800
and 921600) .
The next box is the number
of Data bits, these represent the total number of transitions of the data
transmission (or Tx line) 8 is the standard ( 8 is useful for reading certain
embedded application as it gives two nibbles (4 bit sequences).
The Handshaking property is used
when a full set of connections are used (such as the grey 9 way D-types that
litter my desk). It was used originally to ensure both ends lined up with each
other and the data was sent and received properly. A common handshake was
required between both sender and receiver. Below is the code for the combo box:
Here is
the complete code for serial communication between transmitter and receiver.
Imports System.Data.SqlClient
Imports System.Net.Sockets
Imports System.Text
Public class Form1
{
Public Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Label11.Text = "Hi" + " " +
Form2.TextBox1.Text + " , " + "Welcome you to
PSA"
user = Form2.TextBox1.Text
total = 0
k = 0
If SerialPort1.IsOpen Then
SerialPort1.Close()
End If
Try
With SerialPort1
.PortName = "COM5" ‘ Initilizing
Components…Using code
.BaudRate = 9600
.Parity = IO.Ports.Parity.None
.DataBits = 8
.StopBits = IO.Ports.StopBits.One
.Handshake = IO.Ports.Handshake.None
End With
SerialPort1.Open()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
InBuff
= SerialPort1.ReadExisting() ‘ Receiving Value From
the Serial Port
TextBox1.Text=InBuff
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Seialport.WriteLine("Hello
World!")
End Sub
End Class
OUTPUT:
