通过 C# 使用 HTTP POST 上传图片文件时出现文件格式问题

>SDO REST API - 问题是当我上传文件时，它没有格式，看起来像这样： 98A9799C-CFB1-423B-A4AD-40609282F861 （2.7 MB） 删除 <---此文件需要图片.jpg

该文件只是图片.jpg

public string POST(string URI, string file)
        {
            NetworkCredential credentials = new NetworkCredential();
            credentials.UserName = AppVars.Username;
            credentials.Password = AppVars.Password;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URI);
            request.Credentials = credentials;
            request.Method = WebRequestMethods.Http.Post;
            request.ContentType = "application/x-www-form-urlencoded";
            //I have also tried request.ContentType = "image/jpeg"; and ran into the same issue.
            byte[] bytes = File.ReadAllBytes(file);
            Stream os = null;
            try
            { 
                request.ContentLength = bytes.Length;   
                os = request.GetRequestStream();
                os.Write(bytes, 0, bytes.Length);         
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                if (os != null)
                {
                    os.Close();
                }
            }
            try
            { 
                WebResponse requestResponse = request.GetResponse();
                if (requestResponse == null)
                { return null; }
                StreamReader sr = new StreamReader(requestResponse.GetResponseStream());
                return sr.ReadToEnd().Trim();
            }
            catch (WebException ex)
            {
                MessageBox.Show(ex.Message);
            }
            return null;
        }