private void btnExport_Click(object sender, EventArgs e) { var patients = patientBLL.GetTodayPatients(); var data = patientBLL.Export(patients); string fileName = DateTime.Now.ToString("yyyy-MM-dd") + "营养液发放记录.csv"; string filePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, fileName); File.WriteAllText(filePath, data, Encoding.UTF8); Process.Start(filePath); }