private void tsmiInstrumentDelAll_Click(object sender, EventArgs e) { if (MessageHelper.Confirm("确认删除所有仪器吗?") == DialogResult.Yes) { AccessDBHelper.DeleteInstrumentByHWName(hwFile.HWName); AccessDBHelper.DeleteModelByHWName(hwFile.HWName); AccessDBHelper.DeleteModuleByHWName(hwFile.HWName); root.Nodes.Clear(); } }