关于简单的Excel多页签底层导出_电子底账导出为例（.net core）

[HttpPost]
public ActionResult ExpEleAcc(string linknos)
{
string filenname = null;
CommonResult<string> result = new CommonResult<string>();
try
{
string path = WebSettings.TempDirectory+ "Download" ;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
string template = "****导出模板.xls";
string tempaltePath = $"{env.WebRootPath}{Path.DirectorySeparatorChar}Template{Path.DirectorySeparatorChar}Export{Path.DirectorySeparatorChar}Dec导出模板{Path.DirectorySeparatorChar}{template}";
string guid = CommonHelper.GetGuid();
filenname = Path.Combine(path, "电子底账" + guid + ".xls");
FileInfo info = new FileInfo(tempaltePath);
info.CopyTo(filenname);
HSSFWorkbook hssfworkbookDown;
//读入刚复制的要导出的excel文件
using (FileStream file = new FileStream(filenname, FileMode.Open, FileAccess.Read))
{
hssfworkbookDown = new HSSFWorkbook(file);
file.Close();
}
DecEHeadService DecEHeadService = new DecEHeadService();
//file = new FileStream(filenname, FileMode.Open, FileAccess.ReadWrite);
List<ExpLedgerField> FirstSheetList = DecEHeadService.GetFirstSheetList(linknos, _appUser.CurrentCorpInfo.Site);
List<ExpLedgerField> SecondSheetList = DecEHeadService.GetSecondSheetList(linknos, _appUser.CurrentCorpInfo.Site);
List<ExpLedgerField> LastSheetList = DecEHeadService.GetLastSheetList(linknos, _appUser.CurrentCorpInfo.Site);

// HSSFSheet sheet = (HSSFSheet)hssfworkbookDown.GetSheetAt(0);
//通过sheet 名字得到sheet页
// HSSFWorkbook workbook = new HSSFWorkbook();
// HSSFSheet sheet = (HSSFSheet)workbook.GetSheet("sheet1");//读取名称为sheet1的sheet

HSSFSheet FirstSheet = (HSSFSheet)hssfworkbookDown.GetSheet("商品信息");
HSSFSheet SecondSheet = (HSSFSheet)hssfworkbookDown.GetSheet("许可证信息");
HSSFSheet LastSheet = (HSSFSheet)hssfworkbookDown.GetSheet("许可证VIN信息");

// string create = "2" + "-" + (i + 1).ToString();
// sheet.CopyTo(hssfworkbookDown, create, true, true);
HSSFCellStyle cellstyle = (HSSFCellStyle)hssfworkbookDown.CreateCellStyle();

//第一个页签关于表体得循环
for (int i = 0; i < FirstSheetList.Count; i++)
{

//比较重要的一点  需要创建行
IRow row = FirstSheet.CreateRow(i+3);
if (FirstSheetList[i].G_NO!=null)
{

//获得行   
HSSFCell cell1 = (HSSFCell)FirstSheet.GetRow(i + 3).CreateCell(0);
cell1.SetCellValue(FirstSheetList[i].G_NO);
}

}

//第二个页签关于表体得循环

for (int i = 0; i < SecondSheetList.Count; i++)
{
IRow row = SecondSheet.CreateRow(i + 2);
if (SecondSheetList[i].G_NO != null)
{
HSSFCell cell1 = (HSSFCell)SecondSheet.GetRow(i + 2).CreateCell(0);
cell1.SetCellValue(SecondSheetList[i].G_NO);
}
}

//第三个页签关于表体得循环

for (int i = 0; i < LastSheetList.Count; i++)
{
IRow row = LastSheet.CreateRow(i + 2);
if (LastSheetList[i].G_NO != null)
{
HSSFCell cell1 = (HSSFCell)LastSheet.GetRow(i + 2).CreateCell(0);
cell1.SetCellValue(LastSheetList[i].G_NO);
}

}

//创建文件
FileStream files = new FileStream(filenname, FileMode.Create);
hssfworkbookDown.Write(files);
files.Close();
files.Dispose();
result.Success = true;
// tempaltePath = $"{env.WebRootPath}{Path.DirectorySeparatorChar}Template{Path.DirectorySeparatorChar}Export{Path.DirectorySeparatorChar}Dec导出模板{Path.DirectorySeparatorChar}{template}";

//tempaltePath 模板路径
//filenname 下载路径
//浏览器识别的路径:window.location.href="http://localhost:33795//\TempExport\导出模板_快递无LOT-20190928062051.xls";
string host = "";
// string host =this.Request.Host.Value + @"//\Temp\Download\"+"电子底账" + guid + ".xls";
if (Request.IsHttps == true)
{
host = @"https://" + this.Request.Host.Value + @"//\ emp\Download\" + "电子底账" + guid + ".xls";
}
else
{
host = @"http://" + this.Request.Host.Value + @"//\ emp\Download\" + "电子底账" + guid + ".xls";
}

result.Data = host;
// return Json(result);

#region 拼接成浏览器识别的路径

//浏览器跳转路径： http://localhost:33795//\\Temp\Export\\快递无LOT.NOT_NO-20190927015613.xls

//文件所在的实际物理路径（绝对路径） D: ew v3srcHapp.WebHapp.Web.UITempExport

//获取当前端口， 当前端口名称 ， 文件所在文件夹/Temp/Export/aaa.xml 转换为浏览器识别的路径

//Path = BaseController.Host + BaseController.ApplicationPath+ "\\Temp\Export\\"+Path;
//浏览器识别的路径:window.location.href="http://localhost:33795//\TempExport\导出模板_快递无LOT-20190928062051.xls";
#endregion

}
catch (Exception ex)
{
throw ex;
}
finally
{

}
return Json(result);
}