后端代码

[HttpGet("DownloadExcel")]
  public async Task<dynamic> DownloadExcel(string tmplName)
        {
            var _fileName = "导入表模板.xlsx";
            
            var filePath = @"Files\DownLoad\";
            var NewFile = Path.Combine(filePath, tmplName);
            var stream = new FileStream(NewFile, FileMode.Open);
            return new FileStreamResult(stream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

前端代码 vue 2.0

// 下载导入表模板
    downloadExcel() {
      Axios.get('/api/Excel/DownloadExcel', {
        params: {
          tmplName: 'Excel'
        },
        responseType: 'blob',
      })
          .then(res => {
            const link = document.createElement('a')
            // const blob = new Blob([res.data], { type: 'application/vnd.ms-excel' })
            const blob = new Blob([res.data], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' })
            link.style.display = 'none'
            link.href = URL.createObjectURL(blob)
            link.download = 'xxx入表模板.xlsx'
            document.body.appendChild(link)
            link.click()
            document.body.removeChild(link)
          })
          .catch(error => {
            console.log(error)
          })
    },

注意： 发布的WebAPI项目中有模板文件和文件夹