.net 导出excel 带图片

需要引入 NPOI包　
导出excel：　　　

　　　　/// <summary>
　　　　/// 导出excel
　　　　/// </summary>
　　　　/// <param name="dto"></param>
　　　　/// <returns></returns>

 　　　public FileStreamResult OutPutCustomerVisits(OutPutCustomerVisitsRequest dto)
      {
            var excelName = "导出的excel模板名";
            var workbook = GetWorkbookFromResourceTemplate(excelName, false);
            var sheet = workbook.GetSheetAt(0);

            var datas = new List<object>()//要插入excel中的数据

            var startRowIndex = 1;
            if (datas.Count > 10) sheet.CopyInsertRow(startRowIndex, datas.Count - 10);

            for (int e = 0; e < datas.Count; e++, startRowIndex++)
            {
                var data = datas[e];
                sheet.SetCellValue(startRowIndex, 0, e + 1); //序号
                sheet.SetCellValue(startRowIndex, 1, data.EnterpriseName); 
                sheet.SetCellValue(startRowIndex, 2, data.InterviewRecordType); 
                sheet.SetCellValue(startRowIndex, 3, data.Datetime); 
                sheet.SetCellValue(startRowIndex, 4, data.RecordPerson); 
                sheet.SetCellValue(startRowIndex, 5, data.RecordMember); 
                sheet.SetCellValue(startRowIndex, 6, data.Record); 
                if (data.Imgs.IsNotNullOrWhiteSpace())
                    AddPieChart(sheet, workbook, data.Imgs, startRowIndex, 7);//图片
            }

            return ToFileResult(workbook, $"{excelName}.xlsx", dto.Password);
        }

        /// <summary>
        /// 添加图片到excel中
        /// </summary>
        /// <param name="sheet"></param>
        /// <param name="workbook"></param>
        /// <param name="fileurl"></param>
        /// <param name="row"></param>
        /// <param name="col"></param>
        private void AddPieChart(ISheet sheet, IWorkbook workbook, string fileurl, int row, int col)
        {
            try
            {var res = ;//查服务器上或本地图片
                byte[] bytes = Convert.FromBase64String(res.Data.ToString());//将图片转为byte[]
                if (!string.IsNullOrEmpty(fileurl))
                {
                    //类型
                    PictureType type = PictureType.JPEG;
                    if (fileurl.IndexOf(".png") > -1) type = PictureType.PNG;
                    else if (fileurl.IndexOf(".bmp") > -1) type = PictureType.BMP;
                    int pictureIdx = workbook.AddPicture(bytes, type);
                    // 创建绘图对象并设置图片位置和大小
                    IDrawing patriarch = sheet.CreateDrawingPatriarch();
                    IClientAnchor anchor = workbook.GetCreationHelper().CreateClientAnchor();
                    /*
                     * dx1 dy1 起始单元格中的x,y坐标.
                     * dx2 dy2 结束单元格中的x,y坐标
                     * col1,row1 指定起始的单元格，下标从0开始
                     * col2,row2 指定结束的单元格 ，下标从0开始
                     */
                    anchor.Col1 = col; // 图片所在列的起始位置
                    anchor.Row1 = row; // 图片所在行的起始位置                    
                    anchor.Col2 = col + 1;
                    anchor.Row2 = row + 1;
                    anchor.Dx1 = 0;
                    anchor.Dy1 = 0;
                    anchor.Dx2 = 10;
                    anchor.Dy2 = 30;
                    // 插入图片
                    IPicture picture = patriarch.CreatePicture(anchor, pictureIdx);
                }

            }
            catch (Exception ex)
            {

            }
        }

/// <summary>
/// 从资源模板中加载工作薄
/// </summary>
/// <param name="resourceName">资源名称</param>
/// <returns></returns>
private IWorkbook GetWorkbookFromResourceTemplate(string resourceName)
{
　　using (Stream stream = new MemoryStream((byte[])Resource.ResourceManager.GetObject(resourceName, Resource.Culture)))
　　{
　　　　return stream.GetWorkbook();
　　}
}

//导入excel

public ResponseWrapper ImportCustomerVisits([FromForm] ImportFileDto dto)
{
 if (dto == null) throw new FriendlyException("请求参数不能为空.");

            IWorkbook workbook = dto.File.OpenReadStream().GetWorkbook();
            ISheet sheet = workbook.GetSheetAt(0);
　　　　　　　var table = sheet.ToDataTable();
for (int index = 0; index < table.Rows.Count; index++)
            {
                var row = table.Rows[index];

                var name = row.GetRowCellValue("xx");

                // 读取文件中的图片
                var image = ImgList.Where(img => img.ClientAnchor.Row1 == index + 1)?.First();
                var imgStr = "";
                if (image != null)
                {
                    byte[] pictureData = image.PictureData.Data;
                    //图片类型
                    var imgType = image.PictureData.PictureType;

                    var imgName = Guid.NewGuid() + "";
                    if (imgType == PictureType.PNG) imgName += ".png";
                    else if (imgType == PictureType.JPEG) imgName += ".jpeg";
                    else if (imgType == PictureType.BMP) imgName += ".bmp";

                    imgStr = UploadImageToBase64(pictureData, imgName);
                }


                _xxxRepository.InsertAsync(new xxxModel
                {
    
                });
            }

            _xxxRepository.SaveChanges();

}    

/// <summary>
        /// 将excel中的图片上传到服务器
        /// </summary>
        /// <param name="bytes"></param>
        /// <param name="fileName">图片名，必须加后缀</param>
        /// <param name="scope"></param>
        /// <returns></returns>
        private string UploadImageToBase64(byte[] bytes, string fileName, string scope = "")
        {var res = xxx；//上传图片操作return imgUrl;//服务器图片地址
        }