Example : A Login Form code to open the MDI parent page in VB .NET 2013.
Imports System.Data.SqlClient
Imports System.Text.RegularExpressions
Public Class Login
Dim con As New SqlConnection("Server=.;Database=StudentDB;Trusted_Connection=True")
Private Sub Login_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.StartPosition = FormStartPosition.CenterParent
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedToolWindow
TxtUserName.Focus()
TxtPassword.UseSystemPasswordChar = True
'TxtPassword.PasswordChar = "*"c ' c=character
TxtPassword.MaxLength = 20
End Sub
Private Sub BtnSubmit_Click(sender As Object, e As EventArgs) Handles BtnSubmit.Click
If Trim(TxtUserName.Text) = "" Then
MessageBox.Show("Please Enter User Name", "Login", MessageBoxButtons.OK, MessageBoxIcon.Information)
TxtUserName.Focus()
Exit Sub
End If
If Trim(TxtPassword.Text) = "" Then
MessageBox.Show("Please Enter Password", "Login", MessageBoxButtons.OK, MessageBoxIcon.Information)
TxtPassword.Focus()
Exit Sub
End If
If Not IsValidPassword(TxtPassword.Text) Then
MessageBox.Show(
"Password must contain :" &
vbCrLf &
"• 8 to 20 characters" &
vbCrLf &
"• At least one Uppercase letter" &
vbCrLf &
"• At least one Lowercase letter" &
vbCrLf &
"• At least one Number" &
vbCrLf &
"• At least one Special Symbol",
"Invalid Password",
MessageBoxButtons.OK,
MessageBoxIcon.Warning)
TxtPassword.Focus()
TxtPassword.SelectAll()
Exit Sub
'vbCrLf used for New line.
End If
Try
If con.State = ConnectionState.Open Then
con.Close()
End If
con.Open()
Dim sql As String = "SELECT * FROM ureg WHERE UserName5=@UserName AND Password5=@Password"
Dim cmd As New SqlCommand(sql, con)
cmd.Parameters.AddWithValue("@UserName", TxtUserName.Text.Trim())
cmd.Parameters.AddWithValue("@Password", TxtPassword.Text.Trim())
Dim dr As SqlDataReader
dr = cmd.ExecuteReader()
If dr.Read() Then
MessageBox.Show("Login Successful", "Login", MessageBoxButtons.OK, MessageBoxIcon.Information)
Me.Hide()
MDIParent1.Show()
Else
MessageBox.Show("Invalid User Name or Password", "Login", MessageBoxButtons.OK, MessageBoxIcon.Error)
TxtPassword.Clear()
TxtUserName.Clear()
TxtUserName.Focus()
End If
dr.Close()
con.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Function IsValidPassword(ByVal password As String) As Boolean
Dim pattern As String = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&^#])[A-Za-z\d@$!%*?&^#]{8,20}$"
Return Regex.IsMatch(password, pattern)
End Function
Private Sub BtnReset_Click(sender As Object, e As EventArgs) Handles BtnReset.Click
TxtUserName.Clear()
TxtPassword.Clear()
TxtUserName.Focus()
End Sub
Private Sub ChkShowPassword_CheckedChanged(sender As Object, e As EventArgs) Handles ChkShowPassword.CheckedChanged
If ChkShowPassword.Checked Then
TxtPassword.UseSystemPasswordChar = False
Else
TxtPassword.UseSystemPasswordChar = True
End If
End Sub
Private Sub TxtPassword_TextChanged(sender As Object, e As EventArgs) Handles TxtPassword.TextChanged
If IsValidPassword(TxtPassword.Text) Then
TxtPassword.BackColor = Color.LightGreen
Else
TxtPassword.BackColor = Color.MistyRose
End If
End Sub
End ClassExample : A Change Password Form code in VB .NET 2013.
Imports System.Data.SqlClient
Imports System.Text.RegularExpressions
Public Class ChangePassword
Dim con As New SqlConnection("Server=.;Database=StudentDB;Trusted_Connection=True")
Private Sub ChangePassword_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'Me.StartPosition = FormStartPosition.CenterParent
Me.StartPosition = FormStartPosition.CenterScreen
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedToolWindow
TxtOldPassword.UseSystemPasswordChar = True
TxtNewPassword.UseSystemPasswordChar = True
TxtConfirmPassword.UseSystemPasswordChar = True
TxtUserName.Focus()
End Sub
Private Function IsValidPassword(ByVal password As String) As Boolean
Dim pattern As String = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&^#])[A-Za-z\d@$!%*?&^#]{8,20}$"
Return Regex.IsMatch(password, pattern)
End Function
Private Sub BtnSubmit_Click(sender As Object, e As EventArgs) Handles BtnSubmit.Click
If TxtUserName.Text.Trim() = "" Then
MessageBox.Show("Please enter User Name.")
TxtUserName.Focus()
Exit Sub
End If
If TxtOldPassword.Text.Trim() = "" Then
MessageBox.Show("Please enter Old Password.")
TxtOldPassword.Focus()
Exit Sub
End If
If TxtNewPassword.Text.Trim() = "" Then
MessageBox.Show("Please enter New Password.")
TxtNewPassword.Focus()
Exit Sub
End If
If TxtConfirmPassword.Text.Trim() = "" Then
MessageBox.Show("Please enter Confirm Password.")
TxtConfirmPassword.Focus()
Exit Sub
End If
If TxtNewPassword.Text.Trim() <> TxtConfirmPassword.Text.Trim() Then
MessageBox.Show("New Password and Confirm Password do not match.")
TxtConfirmPassword.Focus()
TxtConfirmPassword.SelectAll()
Exit Sub
End If
If Not IsValidPassword(TxtNewPassword.Text.Trim()) Then
MessageBox.Show("Password must contain:" & vbCrLf &
"• 8 to 20 characters" & vbCrLf &
"• At least one lowercase letter" & vbCrLf &
"• At least one uppercase letter" & vbCrLf &
"• At least one number" & vbCrLf &
"• At least one special symbol",
"Invalid Password",
MessageBoxButtons.OK,
MessageBoxIcon.Warning)
TxtNewPassword.Focus()
TxtNewPassword.SelectAll()
Exit Sub
End If
Try
If con.State = ConnectionState.Open Then
con.Close()
End If
con.Open()
Dim checkSql As String = "SELECT * FROM LoginMaster WHERE UserName5=@UserName AND Password5=@OldPassword"
Dim checkCmd As New SqlCommand(checkSql, con)
checkCmd.Parameters.AddWithValue("@UserName", TxtUserName.Text.Trim())
checkCmd.Parameters.AddWithValue("@OldPassword", TxtOldPassword.Text.Trim())
Dim dr As SqlDataReader = checkCmd.ExecuteReader()
If dr.Read() Then
dr.Close()
Dim updateSql As String = "UPDATE LoginMaster SET Password5=@NewPassword WHERE UserName5=@UserName"
Dim updateCmd As New SqlCommand(updateSql, con)
updateCmd.Parameters.AddWithValue("@NewPassword", TxtNewPassword.Text.Trim())
updateCmd.Parameters.AddWithValue("@UserName", TxtUserName.Text.Trim())
Dim x As Integer = updateCmd.ExecuteNonQuery()
If x > 0 Then
MessageBox.Show("Password Changed Successfully.")
ClearBoxes()
Else
MessageBox.Show("Password Not Changed.")
End If
Else
dr.Close()
MessageBox.Show("Invalid User Name or Old Password.")
TxtOldPassword.Focus()
TxtOldPassword.SelectAll()
End If
con.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub ClearBoxes()
TxtUserName.Clear()
TxtOldPassword.Clear()
TxtNewPassword.Clear()
TxtConfirmPassword.Clear()
TxtUserName.Focus()
End Sub
Private Sub BtnReset_Click(sender As Object, e As EventArgs) Handles BtnReset.Click
ClearBoxes()
End Sub
End ClassExample : A ForgotPassword Form code in VB .NET 2013.
Imports System.Data.SqlClient
Public Class ForgetPassword
Dim con As New SqlConnection("Server=.;Database=RKM;Trusted_Connection=True")
Private Sub BtnGetPassword_Click(sender As Object, e As EventArgs) Handles BtnGetPassword.Click
If TxtUname.Text.Trim() = "" Then
MessageBox.Show("Please enter User Name.")
TxtUname.Focus()
Exit Sub
End If
If TxtEmail.Text.Trim() = "" Then
MessageBox.Show("Please enter Email.")
TxtEmail.Focus()
Exit Sub
End If
If TxtMobileNo.Text.Trim() = "" Then
MessageBox.Show("Please enter Mobile No.")
TxtMobileNo.Focus()
Exit Sub
End If
Try
If con.State = ConnectionState.Open Then
con.Close()
End If
con.Open()
Dim sql As String = "SELECT Password5 FROM ureg WHERE UserName5=@UserName AND Email5=@Email AND Mobile5=@MobileNo AND Dob5=@Dob"
Dim cmd As New SqlCommand(sql, con)
cmd.Parameters.AddWithValue("@UserName", TxtUname.Text.Trim())
cmd.Parameters.AddWithValue("@Email", TxtEmail.Text.Trim())
cmd.Parameters.AddWithValue("@MobileNo", TxtMobileNo.Text.Trim())
cmd.Parameters.AddWithValue("@Dob", DtpDob.Value.Date)
Dim dr As SqlDataReader = cmd.ExecuteReader()
If dr.Read() Then
MessageBox.Show("Your Password is : " & dr("Password5").ToString(),
"Password Found",
MessageBoxButtons.OK,
MessageBoxIcon.Information)
Else
MessageBox.Show("Invalid User Name, Email, Mobile No or Date of Birth.",
"Record Not Found",
MessageBoxButtons.OK,
MessageBoxIcon.Error)
End If
dr.Close()
con.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
'NB : DOB5 field is 'Date' datatype which stores date in the form of yyyy-MM-dd. Date VB design box format - 'custom' and and customformat-'dd-MM-yyyy' in the properties box.
End Sub
Private Sub BtnReset_Click(sender As Object, e As EventArgs) Handles BtnReset.Click
TxtUname.Clear()
TxtEmail.Clear()
TxtMobileNo.Clear()
DtpDob.Value = Date.Today
TxtUname.Focus()
End Sub
Private Sub ForgetPassword_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'Me.StartPosition = FormStartPosition.CenterParent
Me.StartPosition = FormStartPosition.CenterScreen
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedToolWindow
TxtUname.Focus()
End Sub
End Class 
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