[vtkusers] question:about TimerEvent

[王斌]

hello vtkUsers.
  I write an application with vtkWin32RenderWindowInteractor and vtkWin32OpenGLRenderWindow.when i use vtkWin32OpenCLRenderWindow::Render() funtion to render a volume object on the screen,i found it's time is too long,so i want to provide a ProgressBox to the application's users,but i cann't get the vtk's TimerEvent.so if anybody know how, please tell me. thanks in advance.