global.vb

Programming the .NET Compact Framework with vb 源代码

Module Global
   Friend arrForms As New ArrayList

   Friend Function OpenForm(ByVal typeForm As Type) As Form
      Dim frmWork As Form
      Dim boolExists As Boolean = False

      '  Check to see if a form of the
      '     requested type already exists.
      For Each frmWork In arrForms
         If frmWork.GetType Is typeForm Then
            boolExists = True
            Exit For
         End If
      Next

      '  If is does not exist, create it
      '     and add it to the collection.
      If Not boolExists Then
         If typeForm Is GetType(FormTemperature) Then _
                                 frmWork = New FormTemperature
         If typeForm Is GetType(FormPressure) Then _
                                 frmWork = New FormPressure
         If typeForm Is GetType(FormPrecipitation) Then _
                                 frmWork = New FormPrecipitation
         arrForms.Add(frmWork)
      End If

      '  In either case, the reference to the form 
      '     of the correct type is now in frmWork.
      '     Return it.
      Return frmWork
   End Function

   Friend Sub RemoveForm(ByVal frmRemovee As Form)
      arrForms.Remove(frmRemovee)
   End Sub
End Module