.Net Core Api傳Word文件，Vue通過Axios下載Word文件

一、後端

1.Api:

        /// <summary>
        /// 獲取Word文件
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        [Route("{infoid}/word")]
        public async Task<ActionResult> Word(string infoid)
        {
            var physicalPath = "xxx";

            Dictionary<string, string> keyValues = xxx;

            using (FileStream sr = new FileStream(physicalPath + "xxx.docx", FileMode.Open, FileAccess.Read))
            {
                //讀取word模板
                XWPFDocument doc = new XWPFDocument(sr);
                //關鍵字替換
                doc.ReplaceKey(keyValues);

                MemoryStream memoryStream = new MemoryStream();
                doc.Write(memoryStream);

                memoryStream.Seek(0, SeekOrigin.Begin);
                string encodeFilename = HttpUtility.UrlEncode($"VehicleDgTransInfo_{DateTime.Now.ToString("yyyyMMdd")}.docx", Encoding.GetEncoding("UTF-8"));
                Response.Headers.Add("Content-Disposition", "attachment; filename=" + encodeFilename);

                return new FileStreamResult(memoryStream, "application/octet-stream");//文件流方式，指定文件流對應的ContenType。
            }
        }

2.XWPFDocumentExtensions.cs：

using NPOI.XWPF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace GuanWei.XPLP.TMIS.Busi.Api.Extensions
{
    /// <summary>
    /// 擴展方法
    /// </summary>
    public static class XWPFDocumentExtensions
    {
        /// <summary>
        /// 對象轉字段
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        private static Dictionary<string, string> ObjectToDictionary<T>(T obj)
        {
            Type t = obj.GetType();
            PropertyInfo[] pi = t.GetProperties();

            Dictionary<string, string> pairs = new Dictionary<string, string>();

            foreach (var item in pi)
            {
                pairs.Add(t.Name + "." + item.Name, item.GetValue(obj).ToString());
            }

            return pairs;
        }

        /// <summary>
        /// 關鍵字替換
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="doc"></param>
        /// <param name="obj">屬性名爲key，值爲value</param>
        /// <param name="func">key值格式化</param>
        public static void ReplaceKey<T>(this XWPFDocument doc, T obj, Func<string, string> func = null)
        {
            doc.ReplaceKey(ObjectToDictionary(obj), func);
        }

        /// <summary>
        /// 段落關鍵字替換
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="paragraph"></param>
        /// <param name="obj">屬性名爲key，值爲value</param>
        /// <param name="func">key值格式化</param>
        public static void ReplaceKey<T>(this XWPFParagraph paragraph, T obj, Func<string, string> func = null)
        {
            paragraph.ReplaceKey(ObjectToDictionary(obj), func);
        }

        /// <summary>
        /// 關鍵字替換
        /// </summary>
        /// <param name="doc"></param>
        /// <param name="paramList">key爲被替換的關鍵字，value爲替換後的值</param>
        /// <param name="func">key值格式化</param>
        public static void ReplaceKey(this XWPFDocument doc, Dictionary<string, string> paramList, Func<string, string> func = null)
        {
            //遍歷段落
            foreach (var para in doc.Paragraphs)
            {
                //段落關鍵字替換
                para.ReplaceKey(paramList, func);
            }

            //遍歷表格
            var tables = doc.Tables;
            foreach (var table in tables)
            {
                foreach (var row in table.Rows)
                {
                    foreach (var cell in row.GetTableCells())
                    {
                        foreach (var para in cell.Paragraphs)
                        {
                            para.ReplaceKey(paramList);
                        }
                    }
                }
            }
        }

        /// <summary>
        /// 段落關鍵字替換
        /// </summary>
        /// <param name="paragraph"></param>
        /// <param name="paramList">key爲被替換的關鍵字，value爲替換後的值</param>
        /// <param name="func">key值格式化</param>
        public static void ReplaceKey(this XWPFParagraph paragraph, Dictionary<string, string> paramList, Func<string, string> func = null)
        {
            if (func == null)
            {
                func = n => "[" + n + "]";
            }
            string text;
            var runs = paragraph.Runs;

            foreach (var p in paramList)
            {
                if (paragraph.Text.Contains("[" + p.Key + "]"))
                {
                    paragraph.ReplaceText(func.Invoke(p.Key), p.Value);
                }
            }

            //for (int i = 0; i < runs.Count; i++)
            //{
            //    var run = runs[i];
            //    text = run.ToString();
            //    //Type t = model.GetType();
            //    //PropertyInfo[] pi = t.GetProperties();
            //    foreach (var p in paramList)
            //    {
            //        if (text.Contains("[" + p.Key + "]"))
            //        {
            //            text = text.Replace(func.Invoke(p.Key), p.Value);
            //        }
            //    }
            //    runs[i].SetText(text, 0);
            //}
        }

        /// <summary>
        /// 關鍵字替換爲圖片（替換爲圖片時會將圖片所在段落的所有字都清空）
        /// </summary>
        /// <param name="doc"></param>
        /// <param name="key">關鍵字，該方法沒有轉格式化</param>
        /// <param name="pictureData">圖片的文件流</param>
        /// <param name="pictureType">圖片格式默認爲png</param>
        /// <param name="filename">圖片文件名默認爲png</param>
        /// <param name="width">圖片顯示寬度</param>
        /// <param name="height">圖片顯示高度</param>
        public static void ReplaceImg(this XWPFDocument doc, string key, Stream pictureData, int pictureType = (int)PictureType.PNG, string filename = "1.png", int width = 5000000, int height = 4000000)
        {
            //遍歷段落
            foreach (var para in doc.Paragraphs)
            {
                //段落關鍵字替換圖片
                para.ReplaceImg(key, pictureData, pictureType, filename, width, height);
            }
        }

        /// <summary>
        /// 段落關鍵字替換爲圖片（替換爲圖片時會將圖片所在段落的所有字都清空）
        /// </summary>
        /// <param name="paragraph"></param>
        /// <param name="key">關鍵字，該方法沒有轉格式化</param>
        /// <param name="pictureData">圖片的文件流</param>
        /// <param name="pictureType">圖片格式默認爲png</param>
        /// <param name="filename">圖片文件名默認爲png</param>
        /// <param name="width">圖片顯示寬度</param>
        /// <param name="height">圖片顯示高度</param>
        public static void ReplaceImg(this XWPFParagraph paragraph, string key, Stream pictureData, int pictureType = (int)PictureType.PNG, string filename = "1.png", int width = 5000000, int height = 4000000)
        {
            string text;
            var runs = paragraph.Runs;
            for (int i = 0; i < runs.Count; i++)
            {
                var run = runs[i];
                text = run.ToString();
                if (text.Contains(key))
                {
                    text = "";
                    runs[i].AddPicture(pictureData, pictureType, filename, width, height);
                    runs[i].SetText(text, 0);
                }
            }
        }
    }
}

二、前端-

1.Axios：

  // 獲取Word文件
  getWord: (id) => {
    return request({
      url: `${Api}/v1/xxx/${id}/word`,
      method: 'get',
      responseType: 'blob',
      isCustomResponse: true
    })
  },

重點：responseType: 'blob'

2.下載Word：

      xxx.getWord(obj.infoId).then(response => {
        var blob = new Blob([response], {type: 'application/msword'}) // 指定格式爲vnd.ms-excel
        var downloadElement = document.createElement('a')
        var href = window.URL.createObjectURL(blob) // 創建下載的鏈接
        downloadElement.href = href
        downloadElement.download = 'xxx.docx' // 下載後文件名
        document.body.appendChild(downloadElement)
        downloadElement.click() // 點擊下載
        document.body.removeChild(downloadElement) // 下載完成移除元素
        window.URL.revokeObjectURL(href) // 釋放掉blob對象
      })

三、參考：

（1）dotnetcore NPOI：https://github.com/dotnetcore/NPOI

（2）NPOI：https://github.com/tonyqus/npoi

（3）https://www.cnblogs.com/adaGao-frontEnd/p/9386204.html