private void OnCopyImageToClipboardButtonClick(NEventArgs arg)
        {
            NDrawingRasterImageExporter imageExporter = new NDrawingRasterImageExporter(m_DrawingDocument);

            imageExporter.CopyToClipboard();
        }
        private void OnSaveAsRasterImageFileButtonClick(NEventArgs arg)
        {
            NDrawingRasterImageExporter imageExporter = new NDrawingRasterImageExporter(m_DrawingDocument);

            imageExporter.SaveAsImage();
        }
        private void OnShowImageExportButtonClick(NEventArgs arg)
        {
            NDrawingRasterImageExporter imageExporter = new NDrawingRasterImageExporter(m_DrawingDocument);

            imageExporter.ShowDialog(OwnerWindow, true);
        }