使用net core 6 c# 的 NPOI 包，读取excel..xlsx单元格内的图片，并存储到指定服务器

这个是记录，单元格的图片。

直接上代码，直接新建一个 net core api 解决方案，引用一下nuget包。本地创建一个 .xlsx 格式的excel文件

using ICSharpCode.SharpZipLib.Zip;
using Microsoft.AspNetCore.Mvc;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System.Data;
using System.Xml;

namespace ExcelOption.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class ImportExcelController : ControllerBase
    {

        private readonly Microsoft.AspNetCore.Hosting.IHostingEnvironment _hostingEnvironment;

        public ImportExcelController(Microsoft.AspNetCore.Hosting.IHostingEnvironment hostingEnvironment)
        {
            _hostingEnvironment = hostingEnvironment;
        }

        [HttpGet(Name = "dele")]
        public bool dele()
        {
            string zipFileName = "filezip" + ".zip";
            string xlsxFileName = "filexlsx" + ".xlsx";
            var mapPath = _hostingEnvironment.ContentRootPath;
            //业务逻辑处理完了就把原来的文件和解压的文件夹删除
            Directory.Delete(mapPath + @"\" + "filezip", true);
            System.IO.File.Delete(mapPath + @"\" + xlsxFileName);
            //File.Delete(mapPath + "\\" + xlsxFileName);
            System.IO.File.Delete(mapPath + @"\" + zipFileName);

            return true;
        }

        [HttpPost(Name = "ImportExcel_Img")]
        public bool ImportExcel_Img(IFormFileCollection files)
        {

            if (files.Count > 0)
            {
                var file = files[0];
                //读取导入的文件类型
                var fileExt = file.FileName.Substring(file.FileName.LastIndexOf('.')).ToLower();
                if (!fileExt.Equals(".xlsx"))
                {
                    //提示文件类型不正确
                    return false;
                }
                //转换保存zip
                string zipFileName = "filezip" + ".zip";
                string xlsxFileName = "filexlsx" + ".xlsx";
                var mapPath = _hostingEnvironment.ContentRootPath;
                //保存xlsx到服务器
                using (var stream = new FileStream(mapPath + xlsxFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                {
                    file.CopyToAsync(stream);
                }

                //保存zip到服务器
                using (var stream = new FileStream(mapPath  + zipFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                {
                    file.CopyToAsync(stream);
                }
                var dt = ExcelHelper.ExcelToDataTable(mapPath + xlsxFileName);
                //解压，如果解压成功则根据xml处理 (应为方便我就放在ExcelHelper里面了)
                if (UnZipFile(mapPath + zipFileName, out string path))
                {
                    //excel 图片信息
                    List<o_ExcelImgModel> o_ExcelImgModelList = new List<o_ExcelImgModel>();
                    //图片路径文件夹
                    var mediaFolderPath = path + @"xl\media";
                    //判断是否存在此文件夹如果有则处理（如果没有图片他是不会有这个文件夹的）
                    if (System.IO.Directory.Exists(mediaFolderPath))
                    {
                        //解压成功获取xml 节点做处理
                        var exclNode = GetXmlExclNodeList(path);
                        var pictNode = GetXmlPictNodeList(path);

                        //获取图片信息与地址
                        foreach (var nl in exclNode)
                        {
                            XmlElement sondNode = (XmlElement)nl;
                            XmlNodeList descendDodeList = sondNode.ChildNodes;
                            XmlNodeList picNodeList = descendDodeList[0].ChildNodes;

                            XmlNodeList nvPicPrNodeList = picNodeList[0].ChildNodes;
                            XmlElement cNvPrElement = (XmlElement)nvPicPrNodeList.Item(0);
                            string name = cNvPrElement.GetAttribute("name").ToString();

                            XmlNodeList blipFillNodeList = picNodeList[1].ChildNodes;
                            XmlElement picElement = (XmlElement)blipFillNodeList.Item(0);
                            string id = picElement.GetAttribute("r:embed").ToString();

                            foreach (XmlNode xn in pictNode)
                            {
                                XmlElement xe = (XmlElement)xn;
                                if (xe.GetAttribute("Id").ToString() == id)
                                {
                                    var pathOfPicture = xe.GetAttribute("Target").ToString().Replace("..", "").Replace("/", @"\");
                                    pathOfPicture = path + @"xl\" + pathOfPicture;
                                    o_ExcelImgModelList.Add(new o_ExcelImgModel()
                                    {
                                        ID = id,
                                        Name = name,
                                        PathOfPicture = pathOfPicture
                                    });
                                    break;
                                }
                            }
                        }
                        //图片对应dt的哪一列，存到dt然后再循环dt去处理（这个是小编的思维，如果有更好的做法可以随缘发挥）
                        foreach (var item in o_ExcelImgModelList)
                        {
                             //item.PathOfPicture  图片路径取到了，此时你可以存储了
                        }
                    }
                    //现在dt某一列存放了图片的绝对路径就可以通过table去处理了
                    //循环表插入数据及上传
                    foreach (DataRow item in dt.Rows)
                    {
                        //此时你excel转换的 dataTable表的图片字段的 值是："_xlfn.DISPIMG(\"ID_CD49305586E940EF8F78CD3B54A4BCD3\",1)"
                        item["用户名"].ToString(); //"zhao1"

                        //var kkl= item["IMG"].ToString(); //  "_xlfn.DISPIMG(\"ID_CD49305586E940EF8F78CD3B54A4BCD3\",1)"
                        var breakApart = item["IMG"].ToString().Split('\\', '"')[1];
                        var imgPath= o_ExcelImgModelList.FirstOrDefault(x => x.Name == breakApart);

                        //获取图片然后做上传逻辑，这个自己实现我就不多讲了
                    }
                }
                else
                {
                    //解压时报直接返回，这个返回啥类型或者啥数据自己定义就好我这边demo 随缘来个bool意思下
                    return false;
                }
                //业务逻辑处理完了就把原来的文件和解压的文件夹删除
                Directory.Delete(mapPath + "\\" + "filezip", true);
                System.IO.File.Delete(mapPath + "\\" + xlsxFileName);
                //File.Delete(mapPath + "\\" + xlsxFileName);
                System.IO.File.Delete(mapPath + "\\" + zipFileName);
            }
            return true;
        }
        public static string MidStrEx(string sourse, string startstr, string endstr)
        {
            string result = string.Empty;
            int startindex, endindex;
            try
            {
                startindex = sourse.IndexOf(startstr);
                if (startindex == -1)
                    return result;
                string tmpstr = sourse.Substring(startindex + startstr.Length);
                endindex = tmpstr.IndexOf(endstr);
                if (endindex == -1)
                    return result;
                result = tmpstr.Remove(endindex);
            }
            catch (Exception ex)
            {
                Console.Write("MidStrEx Err:" + ex.Message);
            }
            return result;
        }
        /// <summary>
        /// Xml图片表格位置及路径ID
        /// </summary>
        private const string _XmlExcel = @"xl\cellimages.xml";
        /// <summary>
        /// Xml图片路径
        /// </summary>
        private const string _XmlPict = @"xl\_rels\cellimages.xml.rels";

        /// <summary>
        /// 获取图片路径 Xml节点
        /// </summary>
        /// <param name="path">解压后的文件夹路径</param>
        /// <returns></returns>
        private XmlNodeList GetXmlPictNodeList(string path)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(path + _XmlPict);
            XmlNode root = doc.DocumentElement;
            return root.ChildNodes;
        }

        /// <summary>
        /// 获取图片表格位置及路径ID Xml节点
        /// </summary>
        /// <param name="path">解压后的文件夹路径</param>
        /// <returns></returns>
        private XmlNodeList GetXmlExclNodeList(string path)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(path + _XmlExcel);
            XmlNode root = doc.DocumentElement;
            return root.ChildNodes;
        }
        /// <summary>
        /// 解压文件
        /// </summary>
        /// <param name="zipFilePath">压缩文件路径</param>
        /// <param name="path">返回压缩文件夹路径</param>
        /// <param name="unZipDir">解压文件存放路径,为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹</param>
        /// <returns></returns>
        private bool UnZipFile(string zipFilePath, out string path, string unZipDir = null)
        {
            if (zipFilePath == string.Empty)
            {
                path = null;
                return false;
            }

            if (!System.IO.File.Exists(zipFilePath))
            {
                path = null;
                return false;
            }
            //解压文件夹为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹
            if (string.IsNullOrWhiteSpace(unZipDir))
                unZipDir = zipFilePath.Replace(Path.GetFileName(zipFilePath), Path.GetFileNameWithoutExtension(zipFilePath));

            if (!unZipDir.EndsWith("\\"))
                unZipDir += "\\";

            if (!Directory.Exists(unZipDir))
                Directory.CreateDirectory(unZipDir);
            try
            {
                using (ZipInputStream s = new ZipInputStream(System.IO.File.OpenRead(zipFilePath)))
                {

                    ZipEntry theEntry;
                    while ((theEntry = s.GetNextEntry()) != null)
                    {
                        string directoryName = Path.GetDirectoryName(theEntry.Name);
                        string fileName = Path.GetFileName(theEntry.Name);
                        if (directoryName.Length > 0)
                        {
                            Directory.CreateDirectory(unZipDir + directoryName);
                        }
                        if (!directoryName.EndsWith("\\"))
                            directoryName += "\\";
                        if (fileName != String.Empty)
                        {
                            using (FileStream streamWriter = System.IO.File.Create(unZipDir + theEntry.Name))
                            {

                                int size = 2048;
                                byte[] data = new byte[2048];
                                while (true)
                                {
                                    size = s.Read(data, 0, data.Length);
                                    if (size > 0)
                                    {
                                        streamWriter.Write(data, 0, size);
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }
            }
            catch
            {
                path = null;
                return false;
            }
            path = unZipDir;
            return true;
        }
    }
    /// <summary>
    /// excel 图片信息
    /// </summary>
    public class o_ExcelImgModel
    {
        /// <summary>
        /// ID
        /// </summary>
        public string ID { get; set; }
        /// <summary>
        /// 上传图片生成的id
        /// </summary>
        public string Name { get; set; }
        /// <summary>
        /// 图片文件绝对路径
        /// </summary>
        public string PathOfPicture { get; set; }
    }
    public class ExcelHelper
    {
        private static IWorkbook workbook = null;
        private static FileStream fs = null;
        /// <summary>
        /// 将excel中的数据导入到DataTable中
        /// </summary>
        /// <param name="fileName">excel文件路径</param>
        /// <param name="sheetName">excel工作薄sheet的名称</param>
        /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
        /// <returns>返回的DataTable</returns>
        public static DataTable ExcelToDataTable(string fileName, string sheetName = null, bool isFirstRowColumn = true)
        {
            ISheet sheet = null;
            DataTable data = new DataTable();
            int startRow = 0;
            try
            {
                fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
                if (fileName.IndexOf(".xlsx") > 0) // 2007版本
                    workbook = new XSSFWorkbook(fs);
                else if (fileName.IndexOf(".xls") > 0) // 2003版本
                    workbook = new HSSFWorkbook(fs);

                if (sheetName != null)
                {
                    sheet = workbook.GetSheet(sheetName);
                    if (sheet == null) //如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet
                    {
                        sheet = workbook.GetSheetAt(0);
                    }
                }
                else
                {
                    sheet = workbook.GetSheetAt(0);
                }
                if (sheet != null)
                {
                    IRow firstRow = sheet.GetRow(0);
                    int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数

                    if (isFirstRowColumn)
                    {
                        for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                        {
                            ICell cell = firstRow.GetCell(i);
                            if (cell != null)
                            {
                                string cellValue = cell.StringCellValue;
                                if (cellValue != null)
                                {
                                    DataColumn column = new DataColumn(cellValue);
                                    data.Columns.Add(column);
                                }
                            }
                        }
                        startRow = sheet.FirstRowNum + 1;
                    }
                    else
                    {
                        for (int i = firstRow.FirstCellNum; i < cellCount; i++)
                        {
                            DataColumn column = new DataColumn(i.ToString());
                            data.Columns.Add(column);
                        }
                        startRow = sheet.FirstRowNum;
                    }

                    //最后一列的标号
                    int rowCount = sheet.LastRowNum;
                    for (int i = startRow; i <= rowCount; ++i)
                    {
                        IRow row = sheet.GetRow(i);
                        if (row == null) continue; //没有数据的行默认是null　　　　　　　

                        DataRow dataRow = data.NewRow();
                        for (int j = row.FirstCellNum; j < cellCount; ++j)
                        {
                            if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null
                                dataRow[j] = row.GetCell(j).ToString();
                        }
                        data.Rows.Add(dataRow);
                    }
                }

                return data;
            }
            catch (Exception ex)
            {
                Console.WriteLine("Exception: " + ex.Message);
                return null;
            }
        }
    }
}

简单记录一下，有问题的，可以留言，看到就回复