POST方式提交数据，一种众所周知的方式：
html页面中使用form表单提交，接收方式，使用Request.Form[""]或Request.QueryString[""]来获取。
这里介绍另外一种POST方式和接收方式，就是将整个数据作为加入到数据流中提交和接收
接收方式:
Stream s = System.Web.HttpContext.Current.Request.InputStream; byte[] b = new byte[s.Length]; s.Read(b, 0, (int)s.Length); return Encoding.UTF8.GetString(b);
只需要从input Stream中读取byte数据，然后转为string，再解析即可。如果要回复响应消息只需要用：Response.Write() 输出即可（和普通的页面输出一样）。
主动POST发送方式：
HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url);webrequest.Method = "post";byte[] postdatabyte = Encoding.UTF8.GetBytes(postData);webrequest.ContentLength = postdatabyte.Length;Stream stream;stream = webrequest.GetRequestStream();stream.Write(postdatabyte, 0, postdatabyte.Length);stream.Close();using (var httpWebResponse = webrequest.GetResponse())using (StreamReader responseStream = new StreamReader(httpWebResponse.GetResponseStream())){String ret = responseStream.ReadToEnd();T result = XmlDeserialize<T>(ret);return result;} 使用HttpClient对象发送
public static string PostXmlResponse(string url, string xmlString){HttpContent httpContent = new StringContent(xmlString);httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");HttpClient httpClient = new HttpClient();HttpResponseMessage response = httpClient.PostAsync(url, httpContent).Result;if (response.IsSuccessStatusCode){Task<string> t = response.Content.ReadAsStringAsync();return t.Result;}return string.Empty;}
从代码中可以看出仅仅是将字符串转为byte[] 类型，并加入到请求流中，进行请求即可达到POST效果，该种POST方式与上边所提到的接收方式相互配合使用。
下面一种方式是以键值对的方式主动POST传输的。
/// <summary>/// 发起httpPost 请求，可以上传文件/// </summary>/// <param name="url">请求的地址</param>/// <param name="files">文件</param>/// <param name="input">表单数据</param>/// <param name="endoding">编码</param>/// <returns></returns>public static string PostResponse(string url, UpLoadFile[] files, Dictionary<string, string> input, Encoding endoding){string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);request.ContentType = "multipart/form-data; boundary=" + boundary;request.Method = "POST";request.KeepAlive = true;//request.Credentials = CredentialCache.DefaultCredentials;request.Expect = "";MemoryStream stream = new MemoryStream();byte[] line = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");byte[] enterER = Encoding.ASCII.GetBytes("\r\n");提交文件if (files != null){string fformat = "Content-Disposition:form-data; name=\"{0}\";filename=\"{1}\"\r\nContent-Type:{2}\r\n\r\n";foreach (UpLoadFile file in files){stream.Write(line, 0, line.Length); //项目分隔符string s = string.Format(fformat, file.Name, file.FileName, file.Content_Type);byte[] data = Encoding.UTF8.GetBytes(s);stream.Write(data, 0, data.Length);stream.Write(file.Data, 0, file.Data.Length);stream.Write(enterER, 0, enterER.Length); //添加\r\n}}//提交文本字段if (input != null){string format = "--" + boundary + "\r\nContent-Disposition:form-data;name=\"{0}\"\r\n\r\n{1}\r\n"; //自带项目分隔符foreach (string key in input.Keys){string s = string.Format(format, key, input[key]);byte[] data = Encoding.UTF8.GetBytes(s);stream.Write(data, 0, data.Length);}}byte[] foot_data = Encoding.UTF8.GetBytes("--" + boundary + "--\r\n"); //项目最后的分隔符字符串需要带上-- stream.Write(foot_data, 0, foot_data.Length);request.ContentLength = stream.Length;Stream requestStream = request.GetRequestStream(); //写入请求数据stream.Position = 0L;stream.CopyTo(requestStream); //stream.Close();requestStream.Close();try{HttpWebResponse response;try{response = (HttpWebResponse)request.GetResponse();try{using (var responseStream = response.GetResponseStream())using (var mstream = new MemoryStream()){responseStream.CopyTo(mstream);string message = endoding.GetString(mstream.ToArray());return message;}}catch (Exception ex){throw ex;}}catch (WebException ex){//response = (HttpWebResponse)ex.Response;//if (response.StatusCode == HttpStatusCode.BadRequest)//{// using (Stream data = response.GetResponseStream())// {// using (StreamReader reader = new StreamReader(data))// {// string text = reader.ReadToEnd();// Console.WriteLine(text);// }// }//}throw ex;}}catch (Exception ex){throw ex;}}
通过两种主动POST提交 的代码可以看出，其主要区别在于发送前的数据格式 ContentType 的值。
下面列举几种常用的ContentType 值，并简述他们的区别
Content-Type 被指定为 application/x-www-form-urlencoded 时候，传输的数据格式需要如 title=test&sub%5B%5D=1&sub%5B%5D=2&sub%5B%5D=3 所示格式，才能正确解析
Content-Type 被指定为 multipart/form-data 时候，所需格式如下面代码块中所示
Content-Type:multipart/form-data; boundary=----WebKitFormBoundaryrGKCBY7qhFd3TrwA------WebKitFormBoundaryrGKCBY7qhFd3TrwAContent-Disposition: form-data; name="text"title------WebKitFormBoundaryrGKCBY7qhFd3TrwAContent-Disposition: form-data; name="file"; filename="chrome.png"Content-Type: image/pngPNG ... content of chrome.png ...------WebKitFormBoundaryrGKCBY7qhFd3TrwA--
Content-Type 也可以被指定为 application/json ，最终传输格式为 {"title":"test","sub":[1,2,3]} 至于如何接收本人未经尝试，但是可以肯定的讲使用文章开头所说的接收方式接收后转为string类型再
发序列化是可行的。
Content-Type指定为 text/xml ，传输的数据格式为
<?xml version="1.0"?> <methodCall><methodName>examples.getStateName</methodName><params><param><value><i4>41</i4></value></param></params> </methodCall>
此种方式，本人亦未经尝试，接受方式可以参考上文中 application/json 的接收方式。
由于xml的格式传输数据，使用相对较少，相信很多同学亦不知道如何将字符串解析为对象，下文将提供一种转换方式，供参考
XmlDocument doc = new XmlDocument();doc.LoadXml(weixin);//读取xml字符串XmlElement root = doc.DocumentElement;ExmlMsg xmlMsg = new ExmlMsg(){FromUserName = root.SelectSingleNode("FromUserName").InnerText,ToUserName = root.SelectSingleNode("ToUserName").InnerText,CreateTime = root.SelectSingleNode("CreateTime").InnerText,MsgType = root.SelectSingleNode("MsgType").InnerText,};if (xmlMsg.MsgType.Trim().ToLower() == "text"){xmlMsg.Content = root.SelectSingleNode("Content").InnerText;}else if (xmlMsg.MsgType.Trim().ToLower() == "event"){xmlMsg.EventName = root.SelectSingleNode("Event").InnerText;}return xmlMsg; private class ExmlMsg{/// <summary>/// 本公众账号/// </summary>public string ToUserName { get; set; }/// <summary>/// 用户账号/// </summary>public string FromUserName { get; set; }/// <summary>/// 发送时间戳/// </summary>public string CreateTime { get; set; }/// <summary>/// 发送的文本内容/// </summary>public string Content { get; set; }/// <summary>/// 消息的类型/// </summary>public string MsgType { get; set; }/// <summary>/// 事件名称/// </summary>public string EventName { get; set; }} 
