.Net Core创建Api进行文件上传功能

[HttpPost]
        [Route("PostFile")]
        public String PostFile([FromForm] IFormCollection formCollection)
        {
            String result = "Fail";
            if (formCollection.ContainsKey("user"))
            {
                var user = formCollection["user"];
            }
            FormFileCollection fileCollection = (FormFileCollection)formCollection.Files;
            foreach (IFormFile file in fileCollection)
            {
                StreamReader reader = new StreamReader(file.OpenReadStream());
                String content = reader.ReadToEnd();
                String name = file.FileName;
                String filename = @"D:/Test/" + name;
                if (System.IO.File.Exists(filename))
                {
                    System.IO.File.Delete(filename);
                }
                using (FileStream fs = System.IO.File.Create(filename))
                {
                    // 复制文件
                    file.CopyTo(fs);
                    // 清空缓冲区数据
                    fs.Flush();
                }
                result = "Success";
            }
            return result;
        }

 services.Configure<FormOptions>(x =>
            {
         　　　　x.MultipartBodyLengthLimit = 209_715_200;//最大200M
            });

ervices.Configure<FormOptions>(x =>
　　　　　　{
   　　　　 　　x.ValueLengthLimit = int.MaxValue;
    　　　　　　x.MultipartBodyLengthLimit = int.MaxValue;
    　　　　　　x.MemoryBufferThreshold = int.MaxValue;
　　　　　　});