C#post请求上传图片文件中的总结

最近接到需求制作一个款图形化的文件上传工具，api接口已经给了用API测试工具测大致是这样的类型。

请求体：

使用C#winform进行图形化处理
首先就是请求头和请求体的构造。

            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.AllowAutoRedirect = true;
            request.Method = "POST";
            request.Headers.Add("Cookie", cookie);//这是请求头

            string boundary = DateTime.Now.Ticks.ToString("X"); // 随机分隔线
            request.ContentType = "multipart/form-data;charset=utf-8;boundary=" + boundary;
            byte[] itemBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "\r\n");
            byte[] endBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");

            string fileName = System.IO.Path.GetFileName(img);
            //请求体上传文件的信息
            StringBuilder sbHeader = new StringBuilder(string.Format("Content-Disposition:form-data;name=\"media\";filename=\"{0}\"\r\nContent-Type:application/octet-stream\r\n\r\n", fileName));
            byte[] postHeaderBytes = Encoding.UTF8.GetBytes(sbHeader.ToString());

            FileStream fs = new FileStream(img, FileMode.Open, FileAccess.Read);
            byte[] bArr = new byte[fs.Length];
            fs.Read(bArr, 0, bArr.Length);
            fs.Close();

            Stream postStream = request.GetRequestStream();
            postStream.Write(itemBoundaryBytes, 0, itemBoundaryBytes.Length);
            postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
            postStream.Write(bArr, 0, bArr.Length);
            postStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
            postStream.Close();

            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            Stream instream = response.GetResponseStream();
            StreamReader sr = new StreamReader(instream, Encoding.UTF8);
            return sr.ReadToEnd();

主要就是通过Stream 写入request.GetRequestStream();