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 ------WebKitFormBoundaryrGKCBY7qhFd3TrwA Content-Disposition: form-data; name="text" title ------WebKitFormBoundaryrGKCBY7qhFd3TrwA Content-Disposition: form-data; name="file"; filename="chrome.png" Content-Type: image/png PNG ... 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; } }