public async Task <IActionResult> Upload(FileUploadDto dto)
        {
            ResposeResult result = new ResposeResult();

            if (dto.Type == 0)
            {
                return(Ok(result));
            }

            FileModel fileModel   = new FileModel();
            string    filePath    = string.Empty;
            string    webRootPath = _webHostEnvironment.WebRootPath;                            //获取wwwroot文件夹
            string    fileDir     = $"{webRootPath}/upload/{DateTime.Now.ToShortDateString()}"; //文件目录 E:/upload/2020-06-20/


            try
            {
                if (!Directory.Exists(fileDir))
                {
                    Directory.CreateDirectory(fileDir);
                }
                if (dto.Type == 1)
                {
                    IFormFile file    = dto.File;
                    string    fileExt = Path.GetExtension(file.FileName); //文件扩展名,不含“.”
                    if (string.IsNullOrEmpty(fileExt))
                    {
                        result.Msg = "找不到文件扩展名";
                        return(Ok(result));
                    }

                    string newFileName = System.Guid.NewGuid().ToString() + "." + fileExt; //随机生成新的文件名

                    filePath = $"{fileDir}/{newFileName}";                                 //文件路径

                    //通过文件流的方式保存文件
                    using (var stream = new FileStream(filePath, FileMode.Create))
                    {
                        await file.CopyToAsync(stream);
                    }
                }
                else if (dto.Type == 2)
                {
                    Stream fromFile = await HttpClientHelp.Download(dto.Url, HttpMethod.Get);

                    string fileExt = Path.GetExtension(dto.Url); //文件扩展名
                    if (string.IsNullOrEmpty(fileExt))
                    {
                        fileExt = "jpg";
                        //result.Msg = "找不到文件扩展名";
                        //return Ok(result);
                    }
                    string newFileName = System.Guid.NewGuid().ToString() + fileExt; //随机生成新的文件名

                    //已追加的方式 写入文件流
                    filePath = $"{fileDir}/{newFileName}";//文件路径
                    FileHelp.CopyFile(fromFile, filePath, 1024 * 1024);
                }
            }
            catch (Exception e)
            {
                if (System.IO.File.Exists(filePath))
                {
                    System.IO.File.Delete(filePath);
                }
                result.Msg = e.Message;
                return(Ok(result));
            }
            result.IsSuccess       = true;
            result.Code            = HttpStatusCode.Created;
            fileModel.AbsolutePath = filePath;
            fileModel.VirtualPath  = filePath.Replace(webRootPath, "");
            result.Data            = fileModel;
            return(Ok(result));
        }