DataSet数据存入指定路径的Excel文件（套用Excel模板）

如题，将DataSet的所有table的数据存入到同一个Excel的不同的Sheet中，一个DataTable对应一个Sheet,每个Sheet的格式参照Excel模板的样式。

具体如下：

        /// <summary>
        /// 将DataSet数据写入Excel文件（套用模板并分页）
        /// </summary>
        /// <param name="ds">DataSet</param>
        /// <param name="top">行索引</param>
        /// <param name="left">列索引</param>
        /// <param name="lb">显示数据写入的进度label标签</param>
        public void DataSetToExcel(DataSet ds, int top, int left, Label lb)
        {

            int sheetCount = ds.Tables.Count;
            DateTime beforeTime;
            DateTime afterTime;


            //创建一个Application对象并使其可见
            beforeTime = DateTime.Now;
            Excel.Application app = new Excel.Application();
            app.Visible = false;
            afterTime = DateTime.Now;

            //打开模板文件，得到WorkBook对象
            Excel.Workbook workBook = app.Workbooks.Open(templetFile, missing, missing, missing, missing, missing,
                                missing, missing, missing, missing, missing, missing, missing);

            //得到WorkSheet对象
            Excel.Worksheet workSheet = (Excel.Worksheet)workBook.Sheets.get_Item(1);

            //复制sheetCount-个WorkSheet对象
            for (int i = 1; i < sheetCount; i++)
            {
                ((Excel.Worksheet)workBook.Worksheets.get_Item(i)).Copy(missing, workBook.Worksheets[i]);
            }

            //将源DataTable数据写入Excel#region 将源DataTable数据写入Excel
            for (int i = 1; i <= sheetCount; i++)
            {

                //末行索引
                int colCount = ds.Tables[i-1].Columns.Count;

                //获取要写入数据的WorkSheet对象，并重命名
                Excel.Worksheet sheet = (Excel.Worksheet)workBook.Worksheets.get_Item(i);
                sheet.Name = ds.Tables[i-1].TableName;

                //将dt中的数据写入WorkSheet
                for (int j = 0; j < ds.Tables[i-1].Rows.Count; j++)
                {
                    for (int k = 0; k < colCount; k++)
                    {
                        sheet.Cells[top + j, left + k] = ds.Tables[i-1].Rows[j][k].ToString();
                    }
                    lb.Text = "Saving lines: " + sheet.Name + "+" + (1 + j) + "/" + (ds.Tables[i-1].Rows.Count);
                }
            }

            //输出Excel文件并退出
            try
            {
                workBook.SaveAs(outputFile, missing, missing, missing, missing, missing, Excel.XlSaveAsAccessMode.xlExclusive, missing, missing, missing, missing);
                workBook.Close(null, null, null);
                app.Workbooks.Close();
                app.Application.Quit();
                app.Quit();

                System.Runtime.InteropServices.Marshal.ReleaseComObject(workSheet);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workBook);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(app);

                workSheet = null;
                workBook = null;
                app = null;

                GC.Collect();
            }
            catch (Exception e)
            {
                throw e;
            }
            finally
            {
                Process[] myProcesses;
                DateTime startTime;
                myProcesses = Process.GetProcessesByName("Excel");

                //得不到Excel进程ID，暂时只能判断进程启动时间
                foreach (Process myProcess in myProcesses)
                {
                    startTime = myProcess.StartTime;

                    if (startTime > beforeTime && startTime < afterTime)
                    {
                        myProcess.Kill();
                    }
                }
            }

        }