MVC导出Excel之NPOI简单使用（一）

一，NPOI是个啥

NPOI可以对Word或Excel文档等进行读写操作。NPOI 是 POI 项目的 .NET 版本。POI是一个开源的Java读写Excel、WORD等微软OLE2组件文档的项目。想更详细的了解NPOI大家可以到官网：https://archive.codeplex.com/?p=npoi下载文档或自行百度哈。

说说NPOI的使用，NPOI是开源的框架，在vs中我们可以通过nuget来安装：

安装成功或你会在引用中看到多出这5个引用：我们通过这5个dll来实现相关文档的导入到出功能

二，MVC导出Excel

下面通过一个小例子来给简单介绍一下在MVC中如何导出Excel

 public FileResult ToExcel2007()
        {
            
            //数据源
            var source = ProductsService.GetDataTable();

            //保存路径
            string prirkdFilePath = HttpContext.Server.MapPath("~/DownLoad") + "\" + DateTime.Now.ToString("yyyyMM") + "\";
            if (!Directory.Exists(prirkdFilePath))
                Directory.CreateDirectory(prirkdFilePath);

            //文件名称
            string fileNameNoExtension = "测试列表(" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ")";
            string FileName = fileNameNoExtension + ".xlsx";

            //创建工作簿对象
            XSSFWorkbook workbook = new XSSFWorkbook();
            //创建工作表
            ISheet sheet = workbook.CreateSheet("产品列表");

            //创建表头  
            IRow row = sheet.CreateRow(0);
            for (int i = 0; i < source.Columns.Count; i++)
            {
                ICell cell = row.CreateCell(i);
                cell.SetCellValue(source.Columns[i].ColumnName);
            }

            //填充数据
            for (int i = 0; i < source.Rows.Count; i++)
            {
                IRow row1 = sheet.CreateRow(i + 1);
                for (int j = 0; j < source.Columns.Count; j++)
                {
                    ICell cell = row1.CreateCell(j);
                    cell.SetCellValue(source.Rows[i][j].ToString());
                }
            }

            //合并路径
            prirkdFilePath = Path.Combine(prirkdFilePath, FileName);
            //转化为流保存
            FileStream files = new FileStream(prirkdFilePath, FileMode.Create);
            workbook.Write(files);
            files.Close();
            files.Dispose();
            return File(prirkdFilePath,"application/ms-excel",FileName);
        }

前端代码：

<button id="toExcel" onclick="daochu()">导出EXCEL</button>

<script>
function daochu(){
window.open("ToExcel, "_blank");
}

</script>

通过这个例子先了解一下NPOI如何简单的使用，本例是通过NPOI自动创建Excel文档，当然我们导出数据也可以用预先设计好的Excel模板，并且可以根据数据类型的不同给表格添加样式

下面我们通过已有模板，设置单元格样式，并且导出图片到Excel中：

public FileResult ToExcel()
        {
            //数据源
            var source = ProductsService.List();

            //保存路径
            string prirkdFilePath = HttpContext.Server.MapPath("~/DownLoad") + "\" + DateTime.Now.ToString("yyyyMM") + "\";
            if (!Directory.Exists(prirkdFilePath))
                Directory.CreateDirectory(prirkdFilePath);

            //文件名称
            string fileNameNoExtension = "产品列表(" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ")";
            string fileName = fileNameNoExtension + ".xlsx";


            //模板路径
            string priModel = Server.MapPath(@"~/DownLoadExcelTemp产品列表.xlsx");
            //生成模板读取IO流
            FileStream fileStreamRead = new FileStream(priModel, FileMode.Open, FileAccess.Read);
            //创建工作簿对象
            XSSFWorkbook workBook = new XSSFWorkbook(fileStreamRead);

            //预设单元格样式
            XSSFCellStyle comStyle = (XSSFCellStyle)workBook.CreateCellStyle();
            comStyle.Alignment = HorizontalAlignment.Center;//垂直居中

            XSSFCellStyle dateStyle = (XSSFCellStyle)workBook.CreateCellStyle();
            dateStyle.Alignment = HorizontalAlignment.Center;//垂直居中
            XSSFDataFormat format = (XSSFDataFormat)workBook.CreateDataFormat();
            dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd HH:mm:ss");//日期样式

            XSSFCellStyle decimalStyle = (XSSFCellStyle)workBook.CreateCellStyle();
            decimalStyle.Alignment = HorizontalAlignment.Center;
            XSSFDataFormat format2 = (XSSFDataFormat)workBook.CreateDataFormat();
            decimalStyle.DataFormat = format2.GetFormat("0.00");

            //获取工作表
            XSSFSheet xssfSheet = workBook.GetSheetAt(0) as XSSFSheet;
            int rowIndex = 1;
            //填充数据
            foreach (V_Product row in source)
            {
                //创建行
                XSSFRow xssfRow = xssfSheet.CreateRow(rowIndex) as XSSFRow;

                xssfRow.CreateCell(0).SetCellValue(row.ProductNumber);
                xssfRow.Cells[0].CellStyle = comStyle;

                xssfRow.CreateCell(1).SetCellValue(row.ProductName);
                xssfRow.Cells[1].CellStyle = comStyle;

                xssfRow.CreateCell(2);

                xssfRow.CreateCell(3).SetCellValue(row.ProductStandard);
                xssfRow.Cells[3].CellStyle = comStyle;

                xssfRow.CreateCell(4).SetCellValue(Convert.ToDouble(row.Price));
                xssfRow.Cells[4].CellStyle = decimalStyle;

                xssfRow.CreateCell(5).SetCellValue(Convert.ToDouble(row.OrderId));
                xssfRow.Cells[5].CellStyle = comStyle;

                xssfRow.CreateCell(6).SetCellValue(row.CategoryName);
                xssfRow.Cells[6].CellStyle = comStyle;

                xssfRow.CreateCell(7).SetCellValue(row.Creator);
                xssfRow.Cells[7].CellStyle = comStyle;

                xssfRow.CreateCell(8).SetCellValue(Convert.ToDateTime(row.Createtime));
                xssfRow.Cells[8].CellStyle = dateStyle;
//第二列添加图片
                if (!string.IsNullOrEmpty(row.ProductImg))
                {
                    byte[] picBytes = getImageByte(row.ProductImg);
                    int pictureIdx = workBook.AddPicture(picBytes, NPOI.SS.UserModel.PictureType.JPEG);  //添加图片

                    XSSFDrawing patriarch = (XSSFDrawing)xssfSheet.CreateDrawingPatriarch();

                    XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 100, 50, 2, rowIndex, 2 + 1, rowIndex + 1);

                    //图片位置，图片左上角为（col, row）
                    XSSFPicture pict = (XSSFPicture)patriarch.CreatePicture(anchor, pictureIdx);
                    //pict.Resize(); //用图片原始大小来显示
                }
            }
            //合并路径
            prirkdFilePath = Path.Combine(prirkdFilePath, fileName);
            //转化为流保存
            FileStream files = new FileStream(prirkdFilePath, FileMode.Create);
            workBook.Write(files);
            files.Close();
            files.Dispose();

            return File(prirkdFilePath, "application/ms-excel", fileName);
        }

前端代码同上，当然还可以设置其他样式字体，背景色，字体颜色等

三，MVC导入Excel

　　下面例子是上传数据及图片Excel：

/// <summary>
        /// 上传Excel
        /// </summary>
        /// <returns></returns>
        [HttpPost]
        public ActionResult DoUpload(HttpPostedFileBase file)
        {
            //保存路径
            string prirkdFilePath = HttpContext.Server.MapPath("~/Excel") + "\" + DateTime.Now.ToString("yyyyMM") + "\";
            if (!Directory.Exists(prirkdFilePath))
                Directory.CreateDirectory(prirkdFilePath);
            if (file.ContentLength <= 0)
            {
                return Json("导入失败");
            }
            //文件名称
            string fileNameNoExtension = "产品列表(" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ")";
            string fileName = fileNameNoExtension + ".xlsx";

            //合并路径
            prirkdFilePath = Path.Combine(prirkdFilePath, fileName);
            //保存
            file.SaveAs(prirkdFilePath);

            IWorkbook workBook;
            var extension = Path.GetExtension(fileName);
            string fileExt = extension.ToLower();
            using (FileStream fs = new FileStream(prirkdFilePath, FileMode.Open, FileAccess.Read))
            {
                //XSSFWorkbook 适用XLSX格式，HSSFWorkbook 适用XLS格式
                if (fileExt == ".xlsx")
                {
                    workBook = new XSSFWorkbook(fs);
                }
                else if (fileExt == ".xls")
                {
                    workBook = new HSSFWorkbook(fs);
                }
                else
                {
                    workBook = null;
                }
                if (workBook == null) { return null; }
                ISheet sheet = workBook.GetSheetAt(0);

                //表头  
                IRow header = sheet.GetRow(sheet.FirstRowNum);
               
                List<T_Product> productList = new List<T_Product>();
                //数据  
                for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)
                {
                    var product = new T_Product();

                    product.ProductNumber = GetValueType(sheet.GetRow(i).GetCell(0)).ToString();
                    product.ProductName = GetValueType(sheet.GetRow(i).GetCell(1)).ToString();
                    //
                    product.ProductStandard = GetValueType(sheet.GetRow(i).GetCell(3)).ToString();
                    product.Price = Convert.ToDecimal(GetValueType(sheet.GetRow(i).GetCell(4)));
                    
                    productList.Add(product);

                }
                //列总数
                int cellCount = header.LastCellNum;
                //行总数
                int rowCount = sheet.LastRowNum;
　　　　　　　　　　//Ipoi扩展方法
                List<PicturesInfo> picture_list = sheet.GetAllPictureInfos(1, rowCount, 0, cellCount, false);
                foreach (var a in picture_list)
                {
                    string imageName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
                    Image image = Image.FromStream(new MemoryStream(a.PictureData));
                    string path = "";
                    path = Path.Combine(HttpContext.Server.MapPath("~/Upload/Img/"), imageName);
                    image.Save(path);//保存
                    productList[a.MinRow - 1].ProductImg = "/Upload/Img/" + imageName;
                }

                foreach (T_Product t in productList)
                {
                    ProductsService.Add(t);
                }
            }


            return Json("导入成功");
        }

扩展方法来自原园友原文地址：https://www.cnblogs.com/hanzhaoxin/p/4442369.html

前端代码如下：

<form  method="post" enctype="multipart/form-data" action="/DoUpload" >

        <button name="file" type="button" id="btnfile">选择文件</button>
        <button id="btnupload" class="layui-btn"> 上 传 </button>
</form>

就这样吧，颈椎疼   ^…^