c# 文件在线预览功能
using DocumentFormat.OpenXml.Packaging; using DocumentFormat.OpenXml.Wordprocessing; using Microsoft.AspNetCore.Mvc; using Newtonsoft.Json; using OfficeOpenXml; using System; using System.Data; using System.IO; using System.Linq; using System.Threading.Tasks; using HtmlAgilityPack; using DocumentFormat.OpenXml; using System.Text; namespace FilePreview.Controllers { [Route("api/[controller]/[action]")] [ApiController] public class PreviewController : ControllerBase { static PreviewController() { ExcelPackage.LicenseContext = LicenseContext.NonCommercial; } /// <summary> /// 预览Excel /// </summary> /// <param name="filePath"></param> /// <returns></returns> [HttpGet] public async Task<IActionResult> PreviewExcel(string filePath) { //需要安装一个名为"EPPlus"的NuGet包 try { using (ExcelPackage excelPackage = new ExcelPackage(new FileInfo(filePath))) { DataSet dataSet = new DataSet(); foreach (ExcelWorksheet worksheet in excelPackage.Workbook.Worksheets) { System.Data.DataTable dataTable = new System.Data.DataTable(worksheet.Name); for (int col = 1; col <= worksheet.Dimension.Columns; col++) { string columnName = worksheet.Cells[1, col].Value?.ToString(); dataTable.Columns.Add(columnName); } for (int row = 2; row <= worksheet.Dimension.Rows; row++) { DataRow dataRow = dataTable.NewRow(); for (int col = 1; col <= worksheet.Dimension.Columns; col++) { object cellValue = worksheet.Cells[row, col].Value; dataRow[col - 1] = cellValue; } dataTable.Rows.Add(dataRow); } dataSet.Tables.Add(dataTable); } string json = JsonConvert.SerializeObject(dataSet); return Ok(json); } } catch (System.Exception ex) { return Ok(ex.Message); } } /// <summary> /// 预览word /// </summary> /// <param name="filePath"></param> /// <returns></returns> [HttpGet] public async Task<IActionResult> PreviewWord(string filePath) { //需要安装一个名为"Open XML SDK"的NuGet包 try { // 打开 Word 文档 using (WordprocessingDocument doc = WordprocessingDocument.Open(filePath, false)) { // 获取文档主体部分 MainDocumentPart mainPart = doc.MainDocumentPart; Document document = mainPart.Document; Body body = document.Body; string html = "<html><body>"; // 遍历文档中的所有段落 foreach (OpenXmlElement element in body.Elements()) { switch (element) { case Paragraph paragraph: html += ConvertParagraphToHtml(paragraph, mainPart); break; case Table table: html += ConvertTableToHtml(table); break; } } //foreach (Paragraph paragraph in body.Elements<Paragraph>()) //{ // // 将段落转换为 HTML // string paragraphHtml = ConvertParagraphToHtml(paragraph, mainPart); // // 添加段落 HTML 到总体 HTML 字符串中 // html += paragraphHtml; //} html += "</body></html>"; return Ok(html); } } catch (System.Exception ex) { return Ok(ex.Message); } } private static string ConvertParagraphToHtml(Paragraph paragraph, MainDocumentPart mainPart) { string html = "<p>"; // 遍历段落中的所有运行 foreach (Run run in paragraph.Elements<Run>()) { // 遍历运行中的所有图片 foreach (Drawing drawing in run.Elements<Drawing>()) { // 获取图片的嵌入对象 DocumentFormat.OpenXml.Drawing.Blip blip = drawing.Descendants<DocumentFormat.OpenXml.Drawing.Blip>().FirstOrDefault(); if (blip != null) { // 获取图片的 ID string imageId = blip.Embed.Value; // 获取与图片关联的图像部分 ImagePart imagePart = (ImagePart)mainPart.GetPartById(imageId); // 将图像部分的内容转换为 Base64 字符串 string base64String = ConvertImagePartToBase64(imagePart); // 构建 <img> 标签 string imgTag = $"<img src=\"data:image/png;base64,{base64String}\" alt=\"Image\" />"; // 添加到段落 HTML 中 html += imgTag; } } // 获取运行的文本内容 //string text = run.InnerText; string text = ConvertWordXmlToHtml(run.InnerText, run.InnerXml); // 添加文本内容到段落 HTML 中 html += text; } html += "</p>"; return html; } private static string ConvertImagePartToBase64(ImagePart imagePart) { using (Stream stream = imagePart.GetStream()) { using (MemoryStream memoryStream = new MemoryStream()) { stream.CopyTo(memoryStream); byte[] imageBytes = memoryStream.ToArray(); return Convert.ToBase64String(imageBytes); } } } public static string ConvertWordXmlToHtml(string text, string wordXml) { // 创建 HTML 文档对象 HtmlDocument htmlDoc = new HtmlDocument(); htmlDoc.OptionAutoCloseOnEnd = true; // 创建 <span> 元素并设置样式 var spanNode = htmlDoc.CreateElement("span"); var family = Substr(wordXml, "w:ascii=\""); var size = "12"; int number; if (int.TryParse(Substr(wordXml, "w:val=\""), out number)) { size = (int.Parse(Substr(wordXml, "w:val=\"")) / 2).ToString(); } var style = "font-family: " + family + "; font-size: " + size + "px;"; spanNode.SetAttributeValue("style", style); // 将文本内容添加到 <span> 元素中 var textNode = htmlDoc.CreateTextNode(text); spanNode.AppendChild(textNode); // 将 <span> 元素添加到 HTML 文档中 htmlDoc.DocumentNode.AppendChild(spanNode); // 将 HTML 文档转换为字符串 using (var writer = new System.IO.StringWriter()) { htmlDoc.Save(writer); return writer.ToString(); } } public static string Substr(string originalString, string substring) { // 查找子字符串的索引 int startIndex = originalString.IndexOf(substring); if (startIndex != -1) { // 截取子字符串后的一部分字符串 string remainingString = originalString.Substring(startIndex + substring.Length); // 查找第一个引号的索引 int endIndex = remainingString.IndexOf('"'); if (endIndex != -1) { // 利用 Substring 方法截取第一个引号之前的值 string result = remainingString.Substring(0, endIndex); return result; } } return ""; } private static string ConvertTableToHtml(Table table) { StringBuilder htmlBuilder = new StringBuilder(); htmlBuilder.AppendLine("<table style=\"border-collapse: collapse;\">"); foreach (TableRow row in table.Elements<TableRow>()) { htmlBuilder.AppendLine("<tr>"); foreach (TableCell cell in row.Elements<TableCell>()) { htmlBuilder.AppendLine("<td style=\"border: 1px solid black;\">"); foreach (Paragraph paragraph in cell.Elements<Paragraph>()) { foreach (Run run in paragraph.Elements<Run>()) { htmlBuilder.AppendLine(run.InnerText); } } htmlBuilder.AppendLine("</td>"); } htmlBuilder.AppendLine("</tr>"); } htmlBuilder.AppendLine("</table>"); return htmlBuilder.ToString(); } } }
方法调用
Excel文件预览：https://localhost:44368/api/Preview/PreviewExcel?filePath=C:\Users\Administrator\Desktop\001.xlsx
返回一个json结构的dataset
Word文件预览：https://localhost:44368/api/Preview/PreviewWord?filePath=C:\Users\Administrator\Desktop\002.docx
返回一个前端的html页面
