C# 如何为动态生成的工作簿创建下载选项

我使用下面的代码将sql数据转换为excel工作簿..使用此代码.xls文件 是在C://驱动器上创建的。如何使其可下载，以便客户端可以下载？ 帮助我。我正在使用asp.net和c。下面的代码可以很好地将.xls文件存储在

c:/drive

try
    {


        myfilename = subject + "_Sessional" + sessional + "_Batch" + batch;

        string sql = null;
        string data = null;
        int i = 1;
        int j = 0;

        Excel.Application xlApp;
        Excel.Workbook xlWorkBook;
        Excel.Worksheet xlWorkSheet;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Add(misValue);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
        xlWorkSheet.Cells[1, 1] = "Id";
        xlWorkSheet.Cells[1, 2] = "RollNo";
        xlWorkSheet.Cells[1, 3] = "Name";
        xlWorkSheet.Cells[1, 4] = "Branch";
        xlWorkSheet.Cells[1, 5] = "Sem";
        xlWorkSheet.Cells[1, 6] = "Year";
        xlWorkSheet.Cells[1, 7] = "Batch";
        xlWorkSheet.Cells[1, 8] = "Subject";
        xlWorkSheet.Cells[1, 9] = "Sessional";
        xlWorkSheet.Cells[1, 10] = "Attendence";
        xlWorkSheet.Cells[1, 11] = "OutOff";


        using (cnn = new SqlConnection(strConnString))
        {
            cnn.Open();
            sql = "SELECT DISTINCT [st_id], [st_rollno], [st_name], [branch_name], [sem_no], [batch_year] FROM [Student] WHERE (([st_rollno] >=@st_rollno) AND ([st_rollno] <=@st_rollno2) AND ([sem_no] = @sem_no) AND ([branch_name] = @branch_name)) ORDER BY [st_rollno]";

            SqlDataAdapter dscmd = new SqlDataAdapter();
            SqlCommand selectCMD = new SqlCommand(sql, cnn);
            dscmd.SelectCommand = selectCMD;
            selectCMD.Parameters.Add("@st_rollno", SqlDbType.VarChar, 10).Value = firstrollno.Text;
            selectCMD.Parameters.Add("@st_rollno2", SqlDbType.VarChar, 10).Value = lastrollno.Text;
            selectCMD.Parameters.Add("@sem_no", SqlDbType.Int).Value = dpsemno.SelectedItem.Text.ToString();
            selectCMD.Parameters.Add("@branch_name", SqlDbType.VarChar, 5).Value = dpbranchname.SelectedItem.Text.ToString();


            DataSet ds = new DataSet();
            dscmd.Fill(ds);

            for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
            {
                for (j = 0; j <= ds.Tables[0].Columns.Count - 1; j++)
                {

                    data = ds.Tables[0].Rows[i].ItemArray[j].ToString();
                    xlWorkSheet.Cells[i + 2, j + 1] = data;
                    xlWorkSheet.Cells[i + 2, 7] = batch;
                    xlWorkSheet.Cells[i + 2, 8] = subject;
                    xlWorkSheet.Cells[i + 2, 9] = sessional;
                    xlWorkSheet.Cells[i + 2, 11] = outoff;
                }
            }

            xlWorkBook.SaveAs("c:\\" + myfilename + ".xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
            xlWorkBook.Close(true, misValue, misValue);
            xlApp.Quit();

            releaseObject(xlWorkSheet);
            releaseObject(xlWorkBook);
            releaseObject(xlApp);
            lbmsg.Text = "Excel file created,you can find the file in c:\\";
            lbmsg.ForeColor = Color.Green;
            lbmsg.Visible = true;

        }
    }
    catch (SqlException ee)
    {
        lbmsg.Text = ee.Message;
        lbmsg.ForeColor = Color.Green;
        lbmsg.Visible = true;
    }
    finally
    {
        cnn.Close();
    }
}   
    private void releaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
              Label2.Text= "Exception Occured while releasing object " + ex.ToString();
              Label2.ForeColor = Color.Green;
              Label2.Visible = true;

            }

        }

---

非常简单，将此代码放在下载按钮上单击

 Response.Clear();
 Response.ClearHeaders();
 Response.ClearContent();
 Response.AddHeader("content-disposition", "attachment; filename=" + fileName);
 Response.AddHeader("Content-Type", "application/Excel");
 Response.ContentType = "application/vnd.xls";
 Response.AddHeader("Content-Length", file.Length.ToString());
 Response.WriteFile(file.FullName);
 Response.End();

希望这能奏效