Why is my form disappearing when I press ENTER? - vb.net

Question

Good-day,
I'm experiencing a very strange event that just started happening. Whenever I press the ENTER button on my keyboard, I expect the KeyDown event of my textbox to be raised and the corresponding code run. Instead, the form disappears (as if the .Hide() method has been called). When I debug, I see that the code that's supposed to run after the KeyDown event is raised is executing accordingly - but the form just disappears.
I've never encountered this before, so I don't know what to do. Any help would be appreciated. Thanks.
HERE'S THE CODE OF MY FORM:
Imports System.Net
Imports MySql.Data
Imports MySql.Data.MySqlClient
Public Class FormAdd
#Region "VARIABLE DECLARATIONS CODE"
'FOR MySQL DATABASE USE
Public dbConn As MySqlConnection
'FOR CARD NUMBER FORMATTING
Private CF As New CardFormatter
'FOR CARD ENCRYPTION
Dim DES As New System.Security.Cryptography.TripleDESCryptoServiceProvider
Dim Hash As New System.Security.Cryptography.MD5CryptoServiceProvider
Dim encryptedCard As String
#End Region
#Region "SUB-ROUTINES AND FUNCTIONS"
Private Sub GetDBdata()
Try
If TextBoxAccount.Text = "" Then
MessageBox.Show("Sorry, you must enter an ACCOUNT# before proceeding!")
TextBoxAccount.Focus()
Else
dbConn = New MySqlConnection
dbConn.ConnectionString = String.Format("Server={0};Port={1};Uid={2};Password={3};Database=accounting", FormLogin.ComboBoxServerIP.SelectedItem, My.Settings.DB_Port, My.Settings.DB_UserID, My.Settings.DB_Password)
If dbConn.State = ConnectionState.Open Then
dbConn.Close()
End If
dbConn.Open()
Dim dbAdapter As New MySqlDataAdapter("SELECT * FROM customer WHERE accountNumber = " & TextBoxAccount.Text, dbConn)
Dim dbTable As New DataTable
dbAdapter.Fill(dbTable)
If dbTable.Rows.Count > 0 Then
'MessageBox.Show("Customer Account Found!")
Call recordFound()
TextBoxLastName.Text = dbTable.Rows(0).Item("nameLAST")
TextBoxFirstName.Text = dbTable.Rows(0).Item("nameFIRST")
TextBoxSalutation.Text = dbTable.Rows(0).Item("nameSALUTATION")
TextBoxCompanyName.Text = dbTable.Rows(0).Item("nameCOMPANY")
Else
'MessageBox.Show("No Customer Records Found! Please try again!")
Call recordNotFound()
ButtonReset.PerformClick()
End If
dbConn.Close()
End If
Catch ex As Exception
MessageBox.Show("A DATABASE ERROR HAS OCCURED" & vbCrLf & vbCrLf & ex.Message & vbCrLf & _
vbCrLf + "Please report this to the IT/Systems Helpdesk at Ext 131.")
End Try
Dispose()
End Sub
Private Sub SetDBData()
Try
dbConn = New MySqlConnection
dbConn.ConnectionString = String.Format("Server={0};Port={1};Uid={2};Password={3};Database=accounting", FormLogin.ComboBoxServerIP.SelectedItem, My.Settings.DB_Port, My.Settings.DB_UserID, My.Settings.DB_Password)
Dim noCard As Boolean = True
If dbConn.State = ConnectionState.Open Then
dbConn.Close()
End If
dbConn.Open()
Dim dbQuery As String = "SELECT * FROM cc_master WHERE ccNumber = '" & TextBoxCard.Text & "';"
Dim dbData As MySqlDataReader
Dim dbAdapter As New MySqlDataAdapter
Dim dbCmd As New MySqlCommand
dbCmd.CommandText = dbQuery
dbCmd.Connection = dbConn
dbAdapter.SelectCommand = dbCmd
dbData = dbCmd.ExecuteReader
While dbData.Read()
If dbData.HasRows() = True Then
MessageBox.Show("This Credit/Debit Card Already Exists! Try Another!")
noCard = False
Else
noCard = True
End If
End While
dbData.Close()
If noCard = True Then
'PERFORM CARD ENCRYPTION
'PERFORM DATABASE SUBMISSION
Dim dbQuery2 As String = "INSERT INTO cc_master (ccType, ccNumber, ccExpireMonth, ccExpireYear, ccZipcode, ccCode, ccAuthorizedUseStart, ccAuthorizedUseEnd, customer_accountNumber)" & _
"VALUES('" & ComboBoxCardType.SelectedItem & "','" & TextBoxCard.Text & "','" & TextBoxExpireMonth.Text & "','" & TextBoxExpireYear.Text & _
"','" & TextBoxZipCode.Text & "','" & TextBoxCVV2.Text & "','" & Format(DateTimePickerStartDate.Value, "yyyy-MM-dd HH:MM:ss") & "','" & Format(DateTimePickerEndDate.Value, "yyyy-MM-dd HH:MM:ss") & "','" & TextBoxAccount.Text & "');"
Dim dbData2 As MySqlDataReader
Dim dbAdapter2 As New MySqlDataAdapter
Dim dbCmd2 As New MySqlCommand
dbCmd2.CommandText = dbQuery2
dbCmd2.Connection = dbConn
dbAdapter2.SelectCommand = dbCmd2
dbData2 = dbCmd2.ExecuteReader
MessageBox.Show("Credit/Debit Card Information Saved SUCCESSFULLY!")
ButtonReset.PerformClick()
End If
dbConn.Close()
Catch ex As Exception
MessageBox.Show("A DATABASE ERROR HAS OCCURED" & vbCrLf & vbCrLf & ex.Message & vbCrLf & _
vbCrLf + "Please report this to the IT/Systems Helpdesk at Ext 131.")
End Try
Dispose()
End Sub
Private Sub ResetForm()
TextBoxAccount.Clear()
TextBoxLastName.Clear()
TextBoxFirstName.Clear()
TextBoxSalutation.Clear()
TextBoxCard.Clear()
ComboBoxCardType.SelectedItem = ""
TextBoxCompanyName.Clear()
TextBoxCVV2.Clear()
TextBoxExpireMonth.Clear()
TextBoxExpireYear.Clear()
TextBoxZipCode.Clear()
CheckBoxConfirm.Checked = False
TextBoxAccount.SelectionStart = 0
TextBoxAccount.SelectionLength = Len(TextBoxAccount.Text)
TextBoxAccount.Focus()
GroupBoxInputError.Hide()
LabelInstruction.Show()
GroupBox1.Height = 75
End Sub
Private Sub recordFound()
GroupBoxInputError.Text = ""
LabelError.BackColor = Color.Green
LabelError.ForeColor = Color.White
LabelError.Text = "RECORD FOUND!"
GroupBoxInputError.Visible = True
GroupBox1.Height = 345
ButtonReset.Show()
LabelInstruction.Hide()
ComboBoxCardType.Focus()
End Sub
Private Sub recordNotFound()
GroupBoxInputError.Text = ""
LabelError.BackColor = Color.Red
LabelError.ForeColor = Color.White
LabelError.Text = "NO RECORD FOUND!"
GroupBoxInputError.Visible = True
End Sub
'Public Sub encryptCard()
' Try
' DES.Key = Hash.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(My.Settings.Key))
' DES.Mode = System.Security.Cryptography.CipherMode.ECB
' Dim DESEncrypter As System.Security.Cryptography.ICryptoTransform = DES.CreateEncryptor
' Dim Buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(TextBoxCard.Text)
' TextBoxCard.Text = Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
' Catch ex As Exception
' MessageBox.Show("The following error(s) have occurred: " & ex.Message, Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Error)
' End Try
'End Sub
#End Region
#Region "TOOLSTRIP MENU CONTROL CODE"
Private Sub ExitAltF4ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitAltF4ToolStripMenuItem.Click
End
End Sub
#End Region
#Region "BUTTON CONTROLS CODE"
Private Sub ButtonExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonExit.Click
FormMain.Show()
Me.Close()
End Sub
Private Sub ButtonReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonReset.Click
Call ResetForm()
End Sub
Private Sub ButtonSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonSubmit.Click
Call SetDBData()
Call ResetForm()
End Sub
Private Sub ButtonEncrypt_Click(sender As System.Object, e As System.EventArgs) Handles ButtonEncrypt.Click
End Sub
#End Region
#Region "FORM CONTROLS CODE"
Private Sub FormAdd_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Control.CheckForIllegalCrossThreadCalls = False
TextBoxAccount.Focus()
Me.KeyPreview = True
Timer1.Enabled = True
Timer1.Interval = 1
GroupBoxInputError.Hide()
ButtonSubmit.Hide()
ButtonReset.Hide()
GroupBox1.Height = 75
'LabelFooter.Text = "Welcome " & FormLogin.TextBoxUsername.Text() & " | Timestamp: " & Date.Now.ToString
Try
LabelIP.Text = "IP: " & Dns.GetHostEntry(Dns.GetHostName).AddressList(0).ToString
Catch ex As Exception
End Try
'Populate the Card Type combobox with the list of card types from the CardFormatter class
ComboBoxCardType.Items.AddRange(CF.GetCardNames.ToArray)
End Sub
#End Region
#Region "TEXTBOX CONTROLS CODE"
Private Sub TextBoxCard_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBoxCard.GotFocus
TextBoxCard.SelectionStart = 0
TextBoxCard.SelectionLength = Len(TextBoxCard.Text)
Me.Refresh()
End Sub
Private Sub TextBoxCard_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBoxCard.LostFocus
'//CARD VALIDATION//
' This code will check whether the card is a valid number or not. It doesn't check to see if the card is active.
' The code calls on the creditcard function stored in MyModules.vb
Try
If creditcard(TextBoxCard.Text) Then
'MsgBox("Card is Valid")
TextBoxCard.BackColor = Color.GreenYellow
TextBoxCard.ForeColor = Color.Black
GroupBoxInputError.Visible = False
TextBoxCard.Text = CF.GetFormattedString(ComboBoxCardType.Text, TextBoxCard.Text)
Me.Refresh()
Else
BWErrorNotice.RunWorkerAsync()
'MsgBox("Invalid Card")
GroupBoxInputError.Visible = True
TextBoxCard.Focus()
TextBoxCard.Text = TextBoxCard.Text.Replace("-", "")
Me.Refresh()
End If
Catch ex As Exception
End Try
End Sub
Private Sub TextBoxAccount_GotFocus(sender As Object, e As System.EventArgs) Handles TextBoxAccount.GotFocus
TextBoxAccount.SelectAll()
End Sub
Private Sub TextBoxAccount_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBoxAccount.KeyDown
If e.KeyCode = Keys.Enter Then
e.SuppressKeyPress = True
If TextBoxAccount.Text <> "" Then
Call GetDBdata()
Else
MsgBox("You must enter an account number!", MsgBoxStyle.Exclamation, "ATTENTION PLEASE!")
TextBoxAccount.Focus()
End If
End If
'If e.KeyCode = Keys.Enter Then
' e.Handled = True
' SendKeys.Send("{Tab}")
'End If
End Sub
Private Sub TextBoxCard_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBoxCard.MouseClick
TextBoxCard.SelectionStart = 0
TextBoxCard.SelectionLength = Len(TextBoxCard.Text)
TextBoxCard.Text = TextBoxCard.Text.Replace("-", "")
Me.Refresh()
End Sub
#End Region
#Region "OTHER/MISCELLANEOUS CONTROLS CODE"
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
LabelDateTime.Text = DateTime.Now
End Sub
Private Sub BWErrorNotice_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BWErrorNotice.DoWork
Do While Not creditcard(TextBoxCard.Text)
LabelError.BackColor = Color.Black
System.Threading.Thread.Sleep(500)
LabelError.BackColor = Color.Red
System.Threading.Thread.Sleep(500)
Loop
BWErrorNotice.CancelAsync()
End Sub
Private Sub CheckBoxConfirm_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles CheckBoxConfirm.CheckedChanged
If CheckBoxConfirm.Checked = True Then
ButtonSubmit.Show()
Else
ButtonSubmit.Hide()
End If
End Sub
#End Region
End Class

Answer 1

Although what follows will not likely solve the form disappearance problem, it will resolve a downstream issue:
In GetDBData(), you are assigning accountNumber to the value of TextBoxAcount.Text, which must be enclosed with quotes unless you employ a parameter which I strongly recommend you get in the habit of doing.
Dim dbAdapter As New MySqlDataAdapter("SELECT * FROM customer WHERE accountNumber = " & TextBoxAccount.Text, dbConn)
Parameters offer a number of benefits including implicit type conversions, injection attack prevention, and will sometimes even cure unexpected behaviors.

Answer 2

I figured out the problem. I was calling Dispose() at the end of my GetDBData() function - so the form was getting disposed before execution returned back to the TextBox. I deleted it and all is well again.