.net8 webapi 文件上传与下载

效果

新增【FileController.cs】

  /// <summary>
  /// 文件控制器
  /// </summary>
  [Route("api/[controller]/[action]")]
  [ApiController]
  //[Authorize]
  public class FileController : ControllerBase
  {
      /// <summary>
      /// 资源文件夹
      /// </summary>
      private string _filePath = Path.Combine(Directory.GetCurrentDirectory(), "Uploads");

      /// <summary>
      /// 文件下载
      /// </summary>
      /// <param name="fileName">文件名称</param>
      /// <returns></returns>
      [HttpGet]
      public async Task<ActionResult> Download(string fileName)
      {
          HttpResponseMessage response = new HttpResponseMessage();
          var downloadFileName = Path.Combine(_filePath, fileName); ;
          Console.WriteLine(downloadFileName);

          // 判断文件是否存在
          if (!System.IO.File.Exists(downloadFileName))
          {
              response.StatusCode = HttpStatusCode.NotFound;
              return NotFound();
          }
          var memory = new MemoryStream();
          using (var stream2 = new FileStream(downloadFileName, FileMode.Open))
          {
              await stream2.CopyToAsync(memory);
          }
          memory.Position = 0;
          var fileResult = File(memory, "application/octet-stream");
          fileResult.FileDownloadName = fileName;
          return fileResult; // 返回一个文件流
      }

      /// <summary>
      /// 上传文件
      /// </summary>
      /// <param name="file"></param>
      /// <returns></returns>
      [HttpPost]
      public async Task<ActionResult> Upload(IFormFile file)
      {
          if (file == null || file.Length == 0)
              return BadRequest("文件无效");


          // 创建文件夹，如果它不存在的话
          if (!Directory.Exists(_filePath))
          {
              Directory.CreateDirectory(_filePath);
          }

          var path= Path.Combine(_filePath, file.FileName);

          using (var stream = new FileStream(path, FileMode.Create))
          {
              await file.CopyToAsync(stream);
          }

          return Ok("文件上传成功");
      }