private void btnDelete_Click(object sender, EventArgs e) { if (selectedPackage != null && selectedExport == null) { loadedGpkPackages.Remove(selectedPackage); DrawPackages(); logger.Info("Removed package {0}...", selectedPackage.Filename); selectedPackage = null; boxGeneralButtons.Enabled = false; } else if (selectedPackage != null && selectedExport != null) { selectedPackage.ExportList.Remove(selectedPackage.GetObjectKeyByUID(selectedExport.UID)); logger.Info("Removed object {0}...", selectedExport.UID); selectedExport = null; treeMain.Nodes.Remove(treeMain.SelectedNode); } }