ECharts图表导入Excel（一）

最近项目需要将页面上的Echarts图表导入到Excel中，想到两种解决方案：

2. 将图表转成图片写入到Excel;
3. 利用Excel的图标功能生成Echarts图表。

今天来整理第一种方案。

一、获取Echarts的图片数据

var imgData = myChart.getDataURL();//myChart为全局变量，图表对象；getDataURL方法用来获取图片数据，默认图片格式为"png",可以根据需要设置

二、后台处理

 2.1 引用NPOI

2.2 获取数据流

//get the image data and trim "data:image/png;base64,".
string imgData = Request.Form["imgData"];
imgData = imgData.Split(',')[1];
Byte[] bytes = Convert.FromBase64String(imgData);

2.3 写入excle文件

2.2.1 xls文件

//create a hssworkbok
HSSFWorkbook sheets = new HSSFWorkbook();
//create a sheet
HSSFSheet sheet1 = (HSSFSheet)sheets.CreateSheet("your sheet's name");
//create a patriarch
HSSFPatriarch patriarch = (HSSFPatriarch)sheet1.CreateDrawingPatriarch();
//create a anchor
HSSFClientAnchor anchor = new HSSFClientAnchor();
//load the picture and get the picture index in the workbook
int pictIndx = sheets.AddPicture(bytes, PictureType.JPEG);
//create a picture
HSSFPicture pict = (HSSFPicture)patriarch.CreatePicture(anchor, pictIndx);
//Reset the image to the original size.
pict.Resize();
//set the file path
string filePath = "your file path";//相对路径
//write to file
using (FileStream fs = new FileStream(System.Web.HttpContext.Current.Server.MapPath(filePath), FileMode.Create))
{
　　sheets.Write(fs);
}

2.2.2 xlsx文件

//create a workbook.
XSSFWorkbook sheets = new XSSFWorkbook();
//create a sheet.
ISheet sheet1 = sheets.CreateSheet("your sheet's name");
//create a patriarch.
XSSFDrawing patriarch = (XSSFDrawing)sheet1.CreateDrawingPatriarch();
//create a anchor.
XSSFClientAnchor anchor = new XSSFClientAnchor();
//load the picture and get the picture index in the workbook.
int pictIdx = sheets.AddPicture(bytes, XSSFWorkbook.PICTURE_TYPE_PNG);
//create a picture.
IPicture pict = patriarch.CreatePicture(anchor, pictIdx);
//reset the image to the original size.
pict.Resize();

2.4 下载

将文件路径传到前端href或src，触发浏览器下载。

效果图如下：