C# 导入Excel读取图片上传
前言:
相信很多小伙伴都对导入Excel很熟悉,但是怎么把Excel里某一列的图片上传到服务器或OSS上,在本章节重点讲解如何读取Excel图片上传。
一、Excel导入数据到数据库
1.准备好Excel读取的帮助类
在 NuGet 安装 NPOI.dll
using NPOI.HSSF.UserModel; using NPOI.SS.UserModel; using NPOI.XSSF.UserModel; using System; using System.Data; using System.IO; namespace ImportExcel.Api.Helper { 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; } } } }
2.读取Excel数据导入数据库(回顾下我们常用的做法,读取了Excel就存到数据库)
using ImportExcel.Api.Helper; using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web; using System.Web.Http; namespace ImportExcel.Api.Controllers { public class ImportExcelController : ApiController { public bool ImportExcel_Img() { HttpFileCollection files = HttpContext.Current.Request.Files; if (files.Count > 0) { HttpPostedFile file = files[0]; string saveTempPath = "~/Temp/Order"; //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; } var fileName = Guid.NewGuid(); string xlsxFileName = fileName + ".xlsx"; var mapPath = HttpContext.Current.Server.MapPath(saveTempPath); file.SaveAs(mapPath + @"\" + xlsxFileName); var dt = ExcelHelper.ExcelToDataTable(mapPath + @"\" + xlsxFileName); if (dt != null) { //写入数据库逻辑和判断 } } return true; } } }
二、Excel导入数据到数据库并读取图片图文讲解(重点来了)
1.把xlsx文件改为zip文件解压到当前目录
2.进入解压后的目录找到xml文件
图片存放路径XML: \test\xl\drawings\_rels\drawing1.xml.rels
前面我们Excel有四张图片这里也会显示4张图片的路径,通过这个Xml可以知道我们图片存放在哪(注意Id="" 这个地方下面会用到)
访问图片文件夹:\test\xl\media
图片拿到了是不是想问怎么知道这个图片在哪一列上面呢,别急还有一个Xml文件可以获取当前图片所在单元格与行
获取当前图片所在单元格与行Xml:\test\\xl\drawings\drawing1.xml
讲解到现在相信大家有个底了,怎么去获取图片,图片对应哪一行哪一列!
三、Excel导入数据到数据库并且获取图片代码实现与讲解
在做之前我们先准备以下东西
1.读取Excel数据的方法(已经有了)
2.解压zip方法
需要用到的ICSharpCode.SharpZipLib.Zip.dll
/// <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; }
在实现Excel导入数据到数据库的方法做修改
1.准备读取xml的图片信息类
namespace ImportExcel.Api.Model { /// <summary> /// excel 图片信息 /// </summary> public class o_ExcelImgModel { /// <summary> /// ID /// </summary> public string ID { get; set; } /// <summary> /// 行 /// </summary> public int Row { get; set; } /// <summary> /// 单元格 /// </summary> public int Col { get; set; } /// <summary> /// 图片文件绝对路径 /// </summary> public string PathOfPicture { get; set; } } }
2.重点代码演示
using ImportExcel.Api.Helper; using ImportExcel.Api.Model; using System; using System.Collections.Generic; using System.Data; using System.IO; using System.Linq; using System.Net; using System.Net.Http; using System.Web; using System.Web.Http; using System.Xml; namespace ImportExcel.Api.Controllers { public class ImportExcelController : ApiController { public bool ImportExcel_Img() { HttpFileCollection files = HttpContext.Current.Request.Files; if (files.Count > 0) { HttpPostedFile file = files[0]; string saveTempPath = "~/Temp/Order"; //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 var fileName = Guid.NewGuid(); string zipFileName = fileName + ".zip"; string xlsxFileName = fileName + ".xlsx"; var mapPath = HttpContext.Current.Server.MapPath(saveTempPath); //保存xlsx到服务器 file.SaveAs(mapPath + "\\" + xlsxFileName); //保存zip到服务器 file.SaveAs(mapPath + "\\" + zipFileName); 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 (ExcelHelper.UnZipFile(HttpContext.Current.Server.MapPath(saveTempPath) + "\\" + zipFileName, out string path)) { //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); //excel 图片信息 List<o_ExcelImgModel> o_ExcelImgModelList = new List<o_ExcelImgModel>(); //获取图片信息与地址 foreach (var nl in exclNode) { XmlElement sondNode = (XmlElement)nl; XmlNodeList descendDodeList = sondNode.ChildNodes; XmlNodeList fromNodeList = descendDodeList[0].ChildNodes; //取得行号 var row = Convert.ToInt32(fromNodeList.Item(2).InnerText.Trim()); var col = Convert.ToInt32(fromNodeList.Item(0).InnerText.Trim()); XmlNodeList picNodeList = descendDodeList[2].ChildNodes; 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, Col = col, Row = row, 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) { dt.Rows[item.Row - 1][item.Col] += string.IsNullOrWhiteSpace(dt.Rows[item.Row - 1][item.Col].ToString()) ? item.PathOfPicture : "," + item.PathOfPicture; } } //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) { //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 + "\\" + fileName, true); File.Delete(mapPath + "\\" + xlsxFileName); File.Delete(mapPath + "\\" + zipFileName); } return true; } /// <summary> /// Xml图片表格位置及路径ID /// </summary> private const string _XmlExcel = @"\xl\drawings\drawing1.xml"; /// <summary> /// Xml图片路径 /// </summary> private const string _XmlPict = @"\xl\drawings\_rels\drawing1.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; } } }
请认真看代码的备注信息,小编这边提供的基本都是思路,剩下的要需要小伙伴们自由发挥
文章参考:https://www.jeremyjone.com/395/