Namespace Model
  
    Public Class FormList
        Private aFormList As ArrayList
        Private Shared instance As FormList = Nothing
        Public Structure T_FormList
            Public CurrForm As Form.BaseForm
            Public ParForm As Form.BaseForm
        End Structure
        Private Sub New()
            Me.aFormList = New ArrayList
        End Sub

#Region " getinstance "
        Public Shared Function Getinstance() As FormList
            If instance Is Nothing Then
                instance = New FormList
            End If
            Return instance
        End Function
#End Region

#Region " get form list "
        Public Function GetFormList() As ArrayList
            Return Me.aFormList
        End Function
#End Region

#Region " add "
        Public Sub AddForm(ByVal tForm As T_FormList)
            Me.aFormList.Add(tForm)
        End Sub
#End Region

#Region " remove"
        Public Sub RemoveForm(ByVal objForm As Form.BaseForm)
            For Each tForm As T_FormList In Me.aFormList
                If tForm.CurrForm Is objForm Then
                    Me.aFormList.Remove(tForm)
                    Exit For
                End If
            Next
        End Sub
#End Region

#Region "get parent form "
        Public Function GetParentForm(ByVal objForm As Form.BaseForm) As Form.BaseForm
            For Each tForm As T_FormList In Me.aFormList
                If tForm.CurrForm Is objForm Then
                    Return tForm.ParForm
                End If
            Next
        End Function
#End Region

#Region " get children form "
        Public Function GetChildrenForm(ByVal objForm As Form.BaseForm) As ArrayList
            Dim arrChildrenForm As New ArrayList
            For Each tForm As T_FormList In Me.aFormList
                If tForm.ParForm Is objForm Then
                    arrChildrenForm.Add(tForm)
                End If
            Next
            Return arrChildrenForm
        End Function
#End Region

    End Class
End Namespace
 


本文来源：http://blog.csdn.net/Adi_liu/archive/2007/07/02/1675626.aspx