string excelName ="\\"+ DateTime.Now.ToString("yyyyMMddhhmmss") + ".xls";
        string path = Server.MapPath("upfiles") + excelName;
        Excel.Application excel = new Excel.Application();  //Execl的操作类
        //读取保存目标的对象
        Excel.Workbook bookDest = (Excel.WorkbookClass)excel.Workbooks.Add(Missing.Value);
        Excel.Worksheet sheetDest = bookDest.Worksheets.Add(Missing.Value, Missing.Value, Missing.Value, Missing.Value) as Excel.Worksheet;//给工作薄添加一个Sheet   
        sheetDest.Rows.RowHeight = 20;

        sheetDest.Name = strSheetName;

        int rowIndex = 1;
        int colIndex = 0;

        excel.Application.Workbooks.Add(true);

        foreach (DataColumn col in dt.Columns)
        {
            colIndex++;
            sheetDest.Cells[1, colIndex] = col.ColumnName;
        }

        //导入数据行
        foreach (DataRow row in dt.Rows)
        {
            rowIndex++;
            colIndex = 0;
            foreach (DataColumn col in dt.Columns)
            {
                colIndex++;
                sheetDest.Cells[rowIndex, colIndex] = row[col.ColumnName].ToString();
                
            }
        }
        bookDest.Saved = true;
        bookDest.SaveCopyAs(path);

        excel.Quit();
        excel = null;

        GC.Collect();