VB net lab.pdf
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The document contains 9 VB.Net programs with code examples and output. The programs cover topics like counting vowels in a string, checking if a number is even/odd/overflow, calculating compound interest, summing positive and negative numbers from user input, concatenating strings with message box, changing font style based on checkboxes, generating a student enrollment form with combo boxes, creating a dynamic user login form using a database, and implementing a multiple document interface with parent and child forms.
VB net lab.pdf
- 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
- 2. VB.Net Programs Prof. K. Adisesha 2 Output:
- 3. VB.Net Programs 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
- 4. VB.Net Programs Prof. K. Adisesha 4 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:
- 5. VB.Net Programs 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
- 6. VB.Net Programs Prof. K. Adisesha 6 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
- 8. VB.Net Programs Prof. K. Adisesha 8 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click Close() End Sub End Class Output:
- 9. VB.Net Programs 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
- 10. VB.Net Programs Prof. K. Adisesha 10 Output:
- 11. VB.Net Programs 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
- 12. VB.Net Programs Prof. K. Adisesha 12 setStyle() End Sub Private Sub underLineCheck_CheckedChanged(sender As Object, e As EventArgs) Handles underLineCheck.CheckedChanged setStyle() End Sub End Class Output:
- 13. VB.Net Programs Prof. K. Adisesha 13 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
- 14. VB.Net Programs Prof. K. Adisesha 14 Output:
- 15. VB.Net Programs 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)
- 16. VB.Net Programs Prof. K. Adisesha 16 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
- 17. VB.Net Programs Prof. K. Adisesha 17 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:
- 18. VB.Net Programs Prof. K. Adisesha 18 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 Prof. K. Adisesha 19