C# 下载文件 (ASP.NET Core Web API )

using Microsoft.AspNetCore.Mvc;
using System.IO;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.Logging;
using Microsoft.AspNetCore.StaticFiles;
using System.Threading.Tasks;

namespace FCore.Saas.SCM.WebAPI.Areas.Files
{
    public class FilesController : BaseController
    {
        private readonly IHostingEnvironment _hostingEnvironment;
        private readonly ILogger<FilesController> _logger;
        public FilesController(IHostingEnvironment hostingEnvironment, ILogger<FilesController> logger)
        {
            _hostingEnvironment = hostingEnvironment;
            _logger = logger;
        }

        [HttpPost, HttpGet, AllowAnonymous]
        public async Task<IActionResult> DownloadFile(string businessDirectoryName, string fileFullName)
        {
            string filePath = _hostingEnvironment.ContentRootPath + "\\Files\\Upload\\" + businessDirectoryName + "\\" + fileFullName;
            if (!System.IO.File.Exists(filePath))
            {
                return LocalRedirect("/Files/NotFind");
            }
            var memory = new MemoryStream();
            using (var stream = new FileStream(filePath, FileMode.Open))
            {
                await stream.CopyToAsync(memory);
            }
            memory.Position = 0;
            return File(memory, GetContentType(filePath), Path.GetFileName(filePath));
        }

        private string GetContentType(string path)
        {
            var provider = new FileExtensionContentTypeProvider();
            string contentType;
            if (!provider.TryGetContentType(path, out contentType))
            {
                contentType = "application/octet-stream";
            }
            return contentType;
        }
    }
}

 文件：

 请求地址

https://localhost:44359/api/Files/Files/DownloadFile?businessDirectoryName=DownloadTemplate&fileFullName=SaasSCM批量新增商品模板.xlsx