private void toolStripMenuItemCSVExport_Click(object sender, EventArgs e) { if (this.FileControl.SelectedTab is FileTabPage tabPageSelected) { var itemsSelected = tabPageSelected.SequencesSelected; CSVExporter exporter = new CSVExporter(ObjectWriter.HEADERS); foreach (Sequence sequenceAktuell in itemsSelected) { foreach (ObjectInSequence obj in sequenceAktuell.ObjectsInSequence) { exporter.AddLine(ObjectWriter.GetStringData(obj)); } } using (DialogCSVExport dialogExport = new DialogCSVExport()) { dialogExport.Exporter = exporter; dialogExport.ShowDialog(this.FindForm()); } // exporter.WriteCSV(@"d:\temp\test.csv"); } else { // Nothing selected...every TabPage should be a FileTabPage MessageBox.Show("Please select a Page to export.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } }