使用NPOI导出图片到EXCEL

1、首先引用NPOI

2、本例用到的引用

3、在Controller里面添加导出方法

        public ActionResult ExportMsgData(string term)
        {
    
            //为list赋值
            MsgListToExcelForXLSXModel1(list, "");
            return Content("");
        }    

4、导出基础方法

public void MsgListToExcelForXLSXModel1(List<BackMsgProblemList> dt, string file)
{
    XSSFWorkbook xssfworkbook = new XSSFWorkbook();
    ISheet sheet = xssfworkbook.CreateSheet("Test");
    DataTable tblDatas = new DataTable("Datas");
    DataColumn dc = null;


    //赋值给dc，是便于对每一个datacolumn的操作
    dc = tblDatas.Columns.Add("编号", Type.GetType("System.Int32"));
    dc.AutoIncrement = true;//自动增加
    dc.AutoIncrementSeed = 1;//起始为1
    dc.AutoIncrementStep = 1;//步长为1
    dc.AllowDBNull = false;//
    dc = tblDatas.Columns.Add("问题标题", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题状态名称", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片一", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片二", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片三", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片四", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片五", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("问题图片六", Type.GetType("System.String"));

    dc = tblDatas.Columns.Add("报验图片一", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("报验图片二", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("报验图片三", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("报验图片四", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("报验图片五", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("报验图片六", Type.GetType("System.String"));

    dc = tblDatas.Columns.Add("复检图片一", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("复检图片二", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("复检图片三", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("复检图片四", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("复检图片五", Type.GetType("System.String"));
    dc = tblDatas.Columns.Add("复检图片六", Type.GetType("System.String"));
    //表头
    IRow row = sheet.CreateRow(0);
    for (int i = 0; i < tblDatas.Columns.Count; i++)
    {

        ICell cell = row.CreateCell(i);
        cell.SetCellValue(tblDatas.Columns[i].ColumnName);
        //自动适应宽度
        sheet.AutoSizeColumn(i);
        sheet.SetColumnWidth(i, sheet.GetColumnWidth(i));
    }

    //数据
    for (int i = 0; i < dt.Count(); i++)
    {
        IRow row1 = sheet.CreateRow(i + 1);
        ICell cell = row1.CreateCell(0);
        cell.SetCellValue(i + 1);
        cell = row1.CreateCell(1);
        cell.SetCellValue(dt[i].RIP_Name);
        cell = row1.CreateCell(2);
        cell.SetCellValue(dt[i].PB_AllName);
        var arry = dt[i].PB_AllName.Split('>');
        cell = row1.CreateCell(3);
        cell.SetCellValue(arry.Length > 0 ? arry[0] : "");
        cell = row1.CreateCell(4);
        cell.SetCellValue(arry.Length > 1 ? arry[1] : "");
        cell = row1.CreateCell(5);
        cell.SetCellValue(arry.Length > 2 ? arry[2] : "");
        cell = row1.CreateCell(6);
        cell.SetCellValue(arry.Length > 3 ? arry[3] : "");
        cell = row1.CreateCell(7);
        cell.SetCellValue(dt[i].AName);
        cell = row1.CreateCell(8);
        cell.SetCellValue(dt[i].BD_Name);
        cell = row1.CreateCell(9);
        cell.SetCellValue(dt[i].U_Name);
        cell = row1.CreateCell(10);
        cell.SetCellValue(dt[i].H_Code);
        cell = row1.CreateCell(11);
        cell.SetCellValue(dt[i].RIP_DistributName);
        cell = row1.CreateCell(12);
        cell.SetCellValue(dt[i].RIP_SeverityName);
        cell = row1.CreateCell(13);
        cell.SetCellValue(dt[i].HCIC_AddDateStr);
        cell = row1.CreateCell(14);
        cell.SetCellValue(dt[i].RectificationNum.ToString());
        cell = row1.CreateCell(15);
        cell.SetCellValue(dt[i].QuestionStateName);
        if (dt[i].ContentAccListForCreate != null && dt[i].ContentAccListForCreate.Count > 0)
        {
            MsgInsetImg(sheet, row1, dt, i, xssfworkbook, dt[i].ContentAccListForCreate, 16);
        }
        if (dt[i].ContentAccListForInspection != null && dt[i].ContentAccListForInspection.Count > 0)
        {
            MsgInsetImg(sheet, row1, dt, i, xssfworkbook, dt[i].ContentAccListForInspection, 22);
        }
        if (dt[i].ContentAccListForCheck != null && dt[i].ContentAccListForCheck.Count > 0)
        {

            MsgInsetImg(sheet, row1, dt, i, xssfworkbook, dt[i].ContentAccListForCheck, 28);
        }
    }
    /*不能使用如下方法生成Excel，因为在xssfworkbook.Write(stream);操作后会关闭流，导致报错【不能操作已关闭的流】*/
    ////转为字节数组
    //MemoryStream stream = new MemoryStream();
    //xssfworkbook.Write(stream);
    //var buf = stream.ToArray();

    ////保存为Excel文件
    //using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))
    //{
    //    fs.Write(buf, 0, buf.Length);
    //    fs.Flush();
    //}
    /*可以使用下面方式导出-这里数据量多会报错【发现XX.xlsx中部分内容有问题，是否让我们尽量尝试恢复】*/
    //MemoryStream stream = new MemoryStream();
    //xssfworkbook.Write(stream);

    //Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xlsx", DateTime.Now.ToString("yyyyMMddHHmmssfff")));
    //Response.BinaryWrite(stream.ToArray());
    //xssfworkbook = null;
    //stream.Close();
    //stream.Dispose();
    /*最终推荐下面方式*/
    HttpContext curContext = HttpContext.Current;

    MemoryStream ms = new MemoryStream();
    xssfworkbook.Write(ms);
    curContext.Response.AppendHeader("Content-Disposition",
        "attachment;filename=" + HttpUtility.UrlEncode("aaa.xlsx", Encoding.UTF8) + ".xlsx");
    curContext.Response.AddHeader("Content-Length", ms.ToArray().Length.ToString());
    curContext.Response.ContentEncoding = Encoding.UTF8;

    curContext.Response.BinaryWrite(ms.ToArray());
    ms.Close();
    ms.Dispose();
    curContext.Response.End();
}

5、插入图片方法

      private void MsgInsetImg(ISheet sheet, IRow row1, List<BackMsgProblemList> dt, int i, XSSFWorkbook xssfworkbook, List<string> ContentAccList, int colnum)
        {
            for (int j = 0; j < 6; j++)
            {
                //设置图片那的宽高
                sheet.SetColumnWidth(colnum + j, 5845);
                row1.Height = 1731;
                if (ContentAccList.Count <= j)
                {
                    break;
                }
                var dPath = ImageShow + ContentAccList[j];
                try
                {


                    System.Drawing.Image imgOutput = System.Drawing.Bitmap.FromFile(dPath);
                    System.Drawing.Image img = imgOutput.GetThumbnailImage(160, 115, null, IntPtr.Zero);
                    //图片转换为文件流
                    MemoryStream ms = new MemoryStream();
                    img.Save(ms, ImageFormat.Bmp);
                    BinaryReader br = new BinaryReader(ms);
                    var picBytes = ms.ToArray();
                    ms.Close();

                    //插入图片
                    if (picBytes != null && picBytes.Length > 0)
                    {
                        var rows = i + 1;
                        var cols = colnum + j;
                        /* Add Picture to Workbook, Specify picture type as PNG and Get an Index */
                        int pictureIdx = xssfworkbook.AddPicture(picBytes, NPOI.SS.UserModel.PictureType.PNG);  //添加图片
                                                                                                                /* Create the drawing container */
                        XSSFDrawing drawing = (XSSFDrawing)sheet.CreateDrawingPatriarch();
                        /* Create an anchor point */
                        XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 0, 0, cols, rows, 1, 3);

                        /* Invoke createPicture and pass the anchor point and ID */
                        XSSFPicture picture = (XSSFPicture)drawing.CreatePicture(anchor, pictureIdx);
                        /* Call resize method, which resizes the image */
                        picture.Resize();

                        picBytes = null;
                    }
                }
                catch (Exception ex)
                {

                    log.Fatal("--图片导出失败：当前文件路径：" + dPath);
                }

            }
        }

6、导出成果

说明：这里采用的是Excel2007以上版本即：XSSFWorkbook，目前XSSFWorkbook版本的资料较少，希望能帮助大家。

备注：excel宽高采用的不是像素，经过计算大约为宽：36.53125=1像素  高：15.05217391304348=1像素