private void UpdateFieldStructure_Click(object sender, EventArgs e) { int index = this.lstStructure.SelectedIndex; if (this.lstStructure.SelectedIndex >= 0) { var form = new FormUpdateIntermediateStructure(this.currentFile, this.lstStructure.Items[index] as IntermediateStructure); if (form.ShowDialog() == System.Windows.Forms.DialogResult.OK) { this.lstStructure.Items[index] = form.Result; this.currentFile.StrutureList[index] = form.Result; } } }