Winforms - MDI Parent refresh/re-activate - vb.net

Question

I have a MDI Parent form which has a menustrip for the application. My application startup file is the MDI Parent form which on load calls a child login form. Code as below:
Dim myForm As Form = New Login
Dim formResult As DialogResult = myForm.ShowDialog()
If formResult = Windows.Forms.DialogResult.OK Then
If LoginSucceeded = True Then
Me.tabMainMenu.Visible = True
ApplyUserAccess(eApp.DataAccess.DAL_UserSettings.SelectMenuSettingByUserID(glbUserID))
myForm.Dispose()
End If
End If
The menustrip has a Logout label which when clicked disables the menu strip and displays the login form again.
The boolean field LoginSucceeded determines a successful validation of the user credentials and sets the menu according to the access given to that user. My problem is the first time the main menu on the MDI parent is set properly based on the user's access. After logging out and logging in again, i wanted to set the main menu accordingly again which is not happening.
The Form_Load event on the MDI Parent is being executed only once.
Any tips of re-painting the MDI parent when it receives focus the 2nd time onwards.
Thanks,
ZK
My code for the Logoff is as below:
Dim blnLogout As DialogResult = MessageBox.Show("Are You Sure You Want To Logout?", "eApp", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
If blnLogout = Windows.Forms.DialogResult.Yes Then
SetToolbarMenuStyle()
tabMainMenu.Visible = False
LoginSucceeded = False
blnShowLoginTab = True
Dim myForm As Form = New Login
myForm.MdiParent = Me
myForm.WindowState = FormWindowState.Normal
myForm.Show()
End If

Answer 1

Move your login code to its own method in your main form so you can call it multiple times:
Public Class Form1
Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown ValidateLogin()
ValidateLogin()
End Sub
Private Sub LoginLogoutToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles LoginLogoutToolStripMenuItem.Click
ValidateLogin()
End Sub
Private Sub ValidateLogin()
' disable appropriate main form elements so they can't access anything:
Me.tabMainMenu.Visible = False
Using myForm As New Login
If myForm.ShowDialog(Me) = Windows.Forms.DialogResult.OK Then
' login succeeded: re-enable main form elements
Me.tabMainMenu.Visible = True
ApplyUserAccess(eApp.DataAccess.DAL_UserSettings.SelectMenuSettingByUserID(glbUserID))
Else
MessageBox.Show("Login Failed")
End If
End Using
End Sub
End Class
You also don't need the "LoginSucceeded" variable. You can pass a success/failure back to the main form by setting DialogResult to OK in your Login form:
Public Class Login
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If True Then ' <-- perform your check
Me.DialogResult = Windows.Forms.DialogResult.OK ' only return OK if login has succeeded
End If
End Sub
End Class

Answer 2

Here are presumptions on your code, I'm guessing you added the code about on the Form.Load event. The Form.Load event only gets raised when the form is shown for the first time.
According to MSDN
Form.Load Event
Occurs before a form is displayed for the first time.
And now, when you Log-Off, you're setting the visibility of the form to false. So what I suggest is you move your code from the Form.Load event to the Form.VisibleChanged event.
According to MSDN
Form.Load Event
Occurs when the Visible property value changes.