Message box won't display [duplicate] - vb.net

Question

This question already has an answer here:
Not able to show error message if the email/password wrongly entered
(1 answer)
Closed 5 years ago.
I want a message box to appear if the email/ password is incorrect when logging in. However nothing happens with this else statement. Does it need to be placed somewhere else for it to work?
MyConn = New OleDbConnection
MyConn.ConnectionString = connString
MyConn.Open()
str1 = ("SELECT * FROM [UserData] WHERE [Username] = '" & TxtUserName.Text & "' AND [Password] = '" & TxtPassword.Text & "'")
Dim cmd1 As OleDbCommand = New OleDbCommand(str1, MyConn)
dr = cmd1.ExecuteReader
While dr.Read()
userFound = True
TxtPassword.Text = dr("Username").ToString
TxtUserName.Text = dr("Password").ToString
FirstNameToPass = dr("First Name").ToString
LastNameToPass = dr("Last Name").ToString
AddressToPass = dr("Address").ToString
EmailToPass = dr("Email").ToString
If userFound = True Then
UserAccountView.Show()
Me.Hide()
TxtPassword.Clear()
TxtUserName.Clear()
Else
MsgBox("Login is incorrect")
End If
End While
MyConn.Close()
End If

Answer 1

I would simply use a Count() to check if user exists and correct.
Note:
In NoAlias's answer it doesn't solve the problem that userFound will always be true.
So I implemented this solution there might be few errors since i'm not familiar with OleDb but nothing to big hopefully
I also implemented the Using as it is good practice to implement it when working with: IDisposable()
Using MyConn As New OleDbConnection
MyConn.ConnectionString = connString
MyConn.Open()
Dim check As String = "SELECT COUNT(*) FROM [UserData] WHERE [Username] = '" & TxtUserName.Text & "' AND [Password] = '" & TxtPassword.Text & "'"
Dim UserExist As Boolean = False
Dim command As OleDbCommand = New OleDbCommand(check, MyConn)
Using reader As OleDbDataReader = command.ExecuteReader()
While reader.Read()
If reader(0) = 0 Then
UserExist = False
Else
UserExist = True
End If
End While
End Using
If UserExist = True Then
Dim getData As String = "SELECT * FROM [UserData] WHERE [Username] = '" & TxtUserName.Text & "'"
Dim command2 As OleDbCommand = New OleDbCommand(getData, MyConn)
Using reader As OleDbDataReader = command2.ExecuteReader()
While reader.Read()
userFound = True
TxtPassword.Text = dr("Username").ToString
TxtUserName.Text = dr("Password").ToString
FirstNameToPass = dr("First Name").ToString
LastNameToPass = dr("Last Name").ToString
AddressToPass = dr("Address").ToString
EmailToPass = dr("Email").ToString
End While
End Using
Else
MsgBox("Login is incorrect")
End If
MyConn.Close()
End Using

Answer 2

If your SQL returns no results, which will be the case when the credentials are wrong, the MessageBox code will never be called. Put this code block after your While statement.
If userFound = True Then
UserAccountView.Show()
Me.Hide()
TxtPassword.Clear()
TxtUserName.Clear()
Else
MsgBox("Login is incorrect")
End If