HttpWebRequest 上传文件

             // 边界
             string  boundary  =  DateTime.Now.Ticks.ToString( " x " );
            HttpWebRequest uploadRequest  =  (HttpWebRequest)WebRequest.Create(url);//url为上传的地址
            uploadRequest.ContentType  =   " multipart/form-data; boundary= "   +  boundary;
            uploadRequest.Method  =   " POST " ;
            uploadRequest.Accept  =   " */* " ;
            uploadRequest.KeepAlive  =   true ;
            uploadRequest.Headers.Add( " Accept-Language " ,  " zh-cn " );
            uploadRequest.Headers.Add( " Accept-Encoding " ,  " gzip, deflate " );
            uploadRequest.Credentials  =  System.Net.CredentialCache.DefaultCredentials;
            uploadRequest.Headers[ " Cookie " ]  =  cookies;//上传文件时需要的cookies

            WebResponse reponse;
             // 创建一个内存流
            Stream memStream  =   new  MemoryStream();

             // 确定上传的文件路径
             if  ( ! String.IsNullOrEmpty(file))
            {
                boundary  =   " -- "   +  boundary;

                 // 添加上传文件参数格式边界
                 string  paramFormat  =  boundary  +   " \r\nContent-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}\r\n " ;
                NameValueCollection param  =   new  NameValueCollection();
                param.Add( " fname " , Guid.NewGuid().ToString()  +  Path.GetExtension(file));
               
                 // 写上参数
                 foreach  ( string  key  in  param.Keys)
                {
                     string  formitem  =   string .Format(paramFormat, key, param[key]);
                     byte [] formitembytes  =  System.Text.Encoding.UTF8.GetBytes(formitem);
                    memStream.Write(formitembytes,  0 , formitembytes.Length);
                }

                 // 添加上传文件数据格式边界
                 string  dataFormat  =  boundary  +   " \r\nContent-Disposition: form-data; name=\"{0}\";filename=\"{1}\"\r\nContent-Type:application/octet-stream\r\n\r\n " ;
                 string  header  =   string .Format(dataFormat,  " Filedata " , Path.GetFileName(file));
                 byte [] headerbytes  =  System.Text.Encoding.UTF8.GetBytes(header);
                memStream.Write(headerbytes,  0 , headerbytes.Length);

                 // 获取文件内容
                FileStream fileStream  =   new  FileStream(file, FileMode.Open, FileAccess.Read);
                 byte [] buffer  =   new   byte [ 1024 ];
                 int  bytesRead  =   0 ;

                 // 将文件内容写进内存流
                 while  ((bytesRead  =  fileStream.Read(buffer,  0 , buffer.Length))  !=   0 )
                {
                    memStream.Write(buffer,  0 , bytesRead);
                }
                fileStream.Close();

                 // 添加文件结束边界
                 byte [] boundarybytes  =  System.Text.Encoding.UTF8.GetBytes( " \r\n\n "   +  boundary  +   " \r\nContent-Disposition: form-data; name=\"Upload\"\r\n\nSubmit Query\r\n "   +  boundary  +   " -- " );
                memStream.Write(boundarybytes,  0 , boundarybytes.Length);

                 // 设置请求长度
                uploadRequest.ContentLength  =  memStream.Length;
                 // 获取请求写入流
                Stream requestStream  =  uploadRequest.GetRequestStream();
               

                 // 将内存流数据读取位置归零
                memStream.Position  =   0 ;
                 byte [] tempBuffer  =   new   byte [memStream.Length];
                memStream.Read(tempBuffer,  0 , tempBuffer.Length);
                memStream.Close();

                 // 将内存流中的buffer写入到请求写入流
                requestStream.Write(tempBuffer,  0 , tempBuffer.Length);
                requestStream.Close();
            }

             // 获取到上传请求的响应
            reponse  =  uploadRequest.GetResponse();

作者：Louja
出处：http://loujady.cnblogs.com
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此声明，且在文章页面给出原文连接，否则保留追究法律责任的权利。