VB.Net Lab Programs for BCA NEP Syllabus

1. VB.Net Programs
Prof. K. Adisesha 1
C# & Dot Net Lab Programs
Part- B
1. VB.net Program to count the number of Vowels in a string
Public Class Form1
Private Sub resultBtn_Click(sender As Object, e As EventArgs) Handles resultBtn.Click
Dim str1, str2 As String
Dim vcount, i, str1len As Integer
vcount = 0
str1 = stringText.Text
str1len = Len(str1)
str1 = LCase(str1)
For i = 1 To str1len
str2 = Mid(str1, i, 1)
If str2 = "a" Or str2 = "e" Or str2 = "i" Or str2 = "o" Or str2 = "u" Then
vcount = vcount + 1
End If
Next i
resultText.Text = vcount
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Close()
End Sub
End Class

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Prof. K. Adisesha 2
Output:

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Prof. K. Adisesha 3
2. VB.net Program to Check a given is Even or Odd Number or Overflow
if number>10000
Code:
Public Class Form1
Private Sub Label2_Click(sender As Object, e As EventArgs) Handles Label2.Click
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles resultBtn.Click
If valueText.Text Mod 2 = 0 Then
resultText.Text = "EVEN"
Else
resultText.Text = "ODD"
End If
If valueText.Text > 10000 Then
resultText.Text = "Overflow!!!"
End If

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End Sub
Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
valueText.Text = ""
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Close()
End Sub
End Class
Output:

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Prof. K. Adisesha 5
3. VB.net Program to calculate the compound interest
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles resultBtn.Click
Dim P As Integer
Dim R As Integer
Dim n As Integer
P = principleText.Text
R = rateText.Text
n = timeText.Text
compText.Text = P * (1 + (R / 100)) ^ n - 1
End Sub
Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles btnExit.Click
Close()
End Sub

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Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
principleText.Text = ""
rateText.Text = ""
timeText.Text = ""
End Sub
End Class
Output:

7. VB.Net Programs
Prof. K. Adisesha 7
4. VB.Net Program to Display the sum of Positive and negative numbers
using input box
Code:
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub resultBtn_Click(sender As Object, e As EventArgs) Handles resultBtn.Click
Dim arr(), a, b, c, i As Integer
a = CInt(limitText.Text)
ReDim arr(a)
For i = 0 To a - 1 Step 1
arr(i) = CInt(InputBox("Enter elements:"))
If arr(i) > 0 Then
b = b + arr(i)
ElseIf arr(i) < 0 Then
c = c + arr(i)
End If
Next
positiveText.Text = b
negativeText.Text = c
End Sub

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Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Close()
End Sub
End Class
Output:

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Prof. K. Adisesha 9
5. VB.Net Program to concatenate two strings and display result using
Message Box.
Code:
Public Class Form1
Private Sub resultBtn_Click(sender As Object, e As EventArgs) Handles resultBtn.Click
Dim x As String
Dim y As String
x = firstText.Text
y = lastText.Text
MsgBox(firstText.Text + " " + lastText.Text, vbOKCancel)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Close()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles btnclear.Click
firstText.Clear()
lastText.Clear()
End Sub
End Class

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Output:

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Prof. K. Adisesha 11
6. Write a program to change the style of font based on the user’s
choice by using CHECK BOX BUTTON
Public Class Form1
Private Sub setStyle()
Dim style = FontStyle.Regular
If boldCheck.Checked Then
style = style Or FontStyle.Bold
End If
If italicsCheck.Checked Then
style = style Or FontStyle.Italic
End If
If underLineCheck.Checked Then
style = style Or FontStyle.Underline
End If
inputText.Font = New Font(inputText.Font, style)
End Sub
Private Sub boldCheck_CheckedChanged(sender As Object, e As EventArgs) Handles
boldCheck.CheckedChanged
setStyle()
End Sub
Private Sub italicsCheck_CheckedChanged(sender As Object, e As EventArgs) Handles
italicsCheck.CheckedChanged

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setStyle()
End Sub
Private Sub underLineCheck_CheckedChanged(sender As Object, e As EventArgs)
Handles underLineCheck.CheckedChanged
setStyle()
End Sub
End Class
Output:

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7. Write a program to generate a Student Enrolment Details form using
Combo box.
Code:
Public Class Form1
Private Sub dispBtn_Click(sender As Object, e As EventArgs) Handles dispBtn.Click
MsgBox("These are the following details entered: " + vbCrLf + " Name:" + nameText.Text + vbCrLf
+ "Course:" + courseCombo.Text + vbCrLf + "Semester:" + semCombo.Text + vbCrLf + "Marks:" +
marksText.Text, vbOKOnly)
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Close()
End Sub
End Class

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Output:

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Prof. K. Adisesha 15
8. Write a program to generate a Dynamic User login form using
Database.
Code:
Note: Follow the following steps:
➢ Provide MySQL password
➢ Create a Database and provide DB name in Inputbox.
➢ Login table will be created with the given Name in Inputbox
Imports System.Data.Odbc
Public Class Form1
Dim uname As String = InputBox("Enter the UserName of MySql:")
Dim pass As String = InputBox("Enter the password of MySql:")
Dim dB As String = InputBox("Enter the DataBase name")
Dim connectionString As String = "DRIVER={MySQL ODBC 8.0 Unicode
Driver};SERVER=localhost;DATABASE=" + dB + ";UID=" + uname + ";PASSWORD=" + pass
+ ";OPTION=3;"
Public conn As New OdbcConnection(connectionString)
Dim sqlTableCreate As String = "CREATE TABLE users(username varchar(25),password
varchar(25));"
Dim cmdCreate As New OdbcCommand(sqlTableCreate, conn)

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Sub Open()
cmdCreate.ExecuteNonQuery()
End Sub
Private Sub createBtn_Click(sender As Object, e As EventArgs) Handles createBtn.Click
Try
If unameText.Text = "" Or passText.Text = "" Then
MsgBox("Please Provide the values", vbExclamation)
Else
conn.Open()
Dim rows As Integer
Dim sqlInsert As String = "INSERT INTO users(username,password) values(" + "'"
+ unameText.Text + "','" + passText.Text + "')"
Dim cmd As New OdbcCommand(sqlInsert, conn)
rows = cmd.ExecuteNonQuery()
If rows > 0 Then
MsgBox("User Created!", vbOK)
End If
End If
conn.Close()
Catch ex As Exception
MsgBox("Database Error", vbExclamation)
End Try
End Sub
Private Sub loginBtn_Click(sender As Object, e As EventArgs) Handles loginBtn.Click
Try
conn.Open()
Dim sqlSelect As String = "SELECT username,password FROM users WHERE
username=" + "'" + unameText.Text + "' AND " + "password='" + passText.Text + "'"
Dim cmd As New OdbcCommand(sqlSelect, conn)
Dim sqlResult As OdbcDataReader
sqlResult = cmd.ExecuteReader()
If sqlResult.HasRows Then
MsgBox("User Successfully Logged In", vbOK)
conn.Close()
Else
MsgBox("No Match found", vbExclamation)
conn.Close()
End If
Catch ex As Exception
MsgBox("DataBase Error", vbCritical)
End Try

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End Sub
Private Sub clearBtn_Click(sender As Object, e As EventArgs) Handles clearBtn.Click
unameText.Clear()
passText.Clear()
End Sub
Private Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles
showPassCheck.CheckedChanged
If showPassCheck.CheckState = CheckState.Unchecked Then
passText.PasswordChar = "*"
ElseIf showPassCheck.CheckState = CheckState.Checked Then
passText.PasswordChar = ""
End If
End Sub
End Class
Output:

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9. Program to Implement MDI (Multiple Document Interface) Parent Form
Follow the following Steps
➢ To make a form as MDI Form set its IsMdiContainer property as true.
➢ To define a parent form to a child form set MdiParent property.
➢ To arrange the child forms, use LayoutMdi() method.
➢ To get reference of the current child form use ActiveMdiChild property.
➢ To get reference of a control from the child form use its Controls collection.
Output:

19. VB.Net Programs
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