Option Strict On

Public Class clsAppContext
  Inherits ApplicationContext

  Protected Friend WithEvents m_frmMain As frmMain
  Protected Friend WithEvents m_frmSub As frmSuB
  Protected Friend WithEvents m_frmSubSub As frmSubSub

  Public Sub New(ByVal enumForms As AllForms)
    InstanzForm(Nothing, enumForms)
  End Sub

  Private Sub InstanzForm(ByVal sender As Form, _
        ByVal formName As AllForms)
    Dim activeForm As Form
    Select Case formName
      Case AllForms.frmMain
        m_frmMain = New frmMain
        AddHandler m_frmMain.InstanceForm, AddressOf InstanzForm
        activeForm = m_frmMain
      Case AllForms.frmSuB
        m_frmSub = New frmSuB
        AddHandler m_frmSub.InstanceForm, AddressOf InstanzForm
        activeForm = m_frmSub
      Case AllForms.frmSubSub
        m_frmSubSub = New frmSubSub
        AddHandler m_frmSubSub.InstanceForm, AddressOf InstanzForm
        activeForm = m_frmSubSub
    End Select
    activeForm.Show()
    Me.MainForm = activeForm
    If Not (sender Is Nothing) Then sender.Close()
  End Sub

  Protected Overrides Sub OnMainFormClosed(ByVal sender _
        As Object, ByVal e As EventArgs)
    Me.ExitThread()
  End Sub
End Class