.NET微信公众号开发-4.0公众号消息处理
一.前言
微信公众平台的消息处理还是比较完善的，有最基本的文本消息，到图文消息，到图片消息，语音消息，视频消息，音乐消息其基本原理都是一样的，只不过所post的xml数据有所差别，在处理消息之前，我们要认真阅读，官方给我们的文档：http://mp.weixin.qq.com/wiki/14/89b871b5466b19b3efa4ada8e577d45e.html。首先我们从最基本的文本消息处理开始。
<xml>
<ToUserName><![CDATA[toUser]]></ToUserName>
<FromUserName><![CDATA[fromUser]]></FromUserName>
<CreateTime>12345678</CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[你好]]></Content>
</xml>
我们可以看到这是消息处理的一个最基本的模式，有发送者，接受者，创建时间，类型，内容等等。
首先我们来创建一个消息处理的类，这个类用来捕获，所有的消息请求，根据不同的消息请求类型来处理不同的消息回复。
public class WeiXinService { /// <summary> /// TOKEN /// </summary> private const string TOKEN = "finder"; /// <summary> /// 签名 /// </summary> private const string SIGNATURE = "signature"; /// <summary> /// 时间戳 /// </summary> private const string TIMESTAMP = "timestamp"; /// <summary> /// 随机数 /// </summary> private const string NONCE = "nonce"; /// <summary> /// 随机字符串 /// </summary> private const string ECHOSTR = "echostr"; /// <summary> /// /// </summary> private HttpRequest Request { get; set; } /// <summary> /// 构造函数 /// </summary> /// <param name="request"></param> public WeiXinService(HttpRequest request) { this.Request = request; } /// <summary> /// 处理请求，产生响应 /// </summary> /// <returns></returns> public string Response() { string method = Request.HttpMethod.ToUpper(); //验证签名 if (method == "GET") { if (CheckSignature()) { return Request.QueryString[ECHOSTR]; } else { return "error"; } } //处理消息 if (method == "POST") { return ResponseMsg(); } else { return "无法处理"; } } /// <summary> /// 处理请求 /// </summary> /// <returns></returns> private string ResponseMsg() { string requestXml = CommonWeiXin.ReadRequest(this.Request); IHandler handler = HandlerFactory.CreateHandler(requestXml); if (handler != null) { return handler.HandleRequest(); } return string.Empty; } /// <summary> /// 检查签名 /// </summary> /// <param name="request"></param> /// <returns></returns> private bool CheckSignature() { string signature = Request.QueryString[SIGNATURE]; string timestamp = Request.QueryString[TIMESTAMP]; string nonce = Request.QueryString[NONCE]; List<string> list = new List<string>(); list.Add(TOKEN); list.Add(timestamp); list.Add(nonce); //排序 list.Sort(); //拼串 string input = string.Empty; foreach (var item in list) { input += item; } //加密 string new_signature = SecurityUtility.SHA1Encrypt(input); //验证 if (new_signature == signature) { return true; } else { return false; } } }
在来看看我们的首先是如何捕获消息的。首页Default.ashx的代码如下
public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/html"; string postString = string.Empty; if (HttpContext.Current.Request.HttpMethod.ToUpper() == "POST") { //由微信服务接收请求，具体处理请求 WeiXinService wxService = new WeiXinService(context.Request); string responseMsg = wxService.Response(); context.Response.Clear(); context.Response.Charset = "UTF-8"; context.Response.Write(responseMsg); context.Response.End(); } else { string token = "wei2414201"; if (string.IsNullOrEmpty(token)) { return; } string echoString = HttpContext.Current.Request.QueryString["echoStr"]; string signature = HttpContext.Current.Request.QueryString["signature"]; string timestamp = HttpContext.Current.Request.QueryString["timestamp"]; string nonce = HttpContext.Current.Request.QueryString["nonce"]; if (!string.IsNullOrEmpty(echoString)) { HttpContext.Current.Response.Write(echoString); HttpContext.Current.Response.End(); } } }
从上面的代码中我们可以看到WeiXinService.cs类中的消息相应至关重要。
/// <summary> /// 处理请求 /// </summary> /// <returns></returns> private string ResponseMsg() { string requestXml = CommonWeiXin.ReadRequest(this.Request); IHandler handler = HandlerFactory.CreateHandler(requestXml); if (handler != null) { return handler.HandleRequest(); } return string.Empty; }
IHandler是一个消息处理接口，其下面有EventHandler，TextHandler处理类实现这个接口。代码如下
/// <summary> /// 处理接口 /// </summary> public interface IHandler { /// <summary> /// 处理请求 /// </summary> /// <returns></returns> string HandleRequest(); }
EventHandler
class EventHandler : IHandler { /// <summary> /// 请求的xml /// </summary> private string RequestXml { get; set; } /// <summary> /// 构造函数 /// </summary> /// <param name="requestXml"></param> public EventHandler(string requestXml) { this.RequestXml = requestXml; } /// <summary> /// 处理请求 /// </summary> /// <returns></returns> public string HandleRequest() { string response = string.Empty; EventMessage em = EventMessage.LoadFromXml(RequestXml); if (em.Event.Equals("subscribe", StringComparison.OrdinalIgnoreCase))//用来判断是不是首次关注 { PicTextMessage tm = new PicTextMessage();//我自己创建的一个图文消息处理类 tm.ToUserName = em.FromUserName; tm.FromUserName = em.ToUserName; tm.CreateTime = CommonWeiXin.GetNowTime(); response = tm.GenerateContent(); } return response; } }
TextHandler
/// <summary> /// 文本信息处理类 /// </summary> public class TextHandler : IHandler { string openid { get; set; } string access_token { get; set; } /// <summary> /// 请求的XML /// </summary> private string RequestXml { get; set; } /// <summary> /// 构造函数 /// </summary> /// <param name="requestXml">请求的xml</param> public TextHandler(string requestXml) { this.RequestXml = requestXml; } /// <summary> /// 处理请求 /// </summary> /// <returns></returns> public string HandleRequest() { string response = string.Empty; TextMessage tm = TextMessage.LoadFromXml(RequestXml); string content = tm.Content.Trim(); if (string.IsNullOrEmpty(content)) { response = "您什么都没输入，没法帮您啊。"; } else { string username = System.Configuration.ConfigurationManager.AppSettings["weixinid"].ToString(); AccessToken token = AccessToken.Get(username); access_token = token.access_token; openid = tm.FromUserName; response = HandleOther(content); } tm.Content = response; //进行发送者、接收者转换 string temp = tm.ToUserName; tm.ToUserName = tm.FromUserName; tm.FromUserName = temp; response = tm.GenerateContent(); return response; } /// <summary> /// 处理其他消息 /// </summary> /// <param name="tm"></param> /// <returns></returns> private string HandleOther(string requestContent) { string response = string.Empty; if (requestContent.Contains("你好") || requestContent.Contains("您好")) { response = "您也好~"; }else if (requestContent.Contains("openid") || requestContent.Contains("id") || requestContent.Contains("ID"))//用来匹配用户输入的关键字 { response = "你的Openid: "+openid; } else if (requestContent.Contains("token") || requestContent.Contains("access_token")) { response = "你的access_token: " + access_token; }else { response = "试试其他关键字吧。"; } return response; } }
HandlerFactory
/// <summary> /// 处理器工厂类 /// </summary> public class HandlerFactory { /// <summary> /// 创建处理器 /// </summary> /// <param name="requestXml">请求的xml</param> /// <returns>IHandler对象</returns> public static IHandler CreateHandler(string requestXml) { IHandler handler = null; if (!string.IsNullOrEmpty(requestXml)) { //解析数据 XmlDocument doc = new System.Xml.XmlDocument(); doc.LoadXml(requestXml); XmlNode node = doc.SelectSingleNode("/xml/MsgType"); if (node != null) { XmlCDataSection section = node.FirstChild as XmlCDataSection; if (section != null) { string msgType = section.Value; switch (msgType) { case "text": handler = new TextHandler(requestXml); break; case "event": handler = new EventHandler(requestXml); break; } } } } return handler; } }
在这里基本的一些类已经完成了，现在我们来完成，关注我们的微信公众号，我们就发送一条图文消息，同时输入我们的一些关键字，返回一些消息，比如输入id返回用户的openid等等。
二.PicTextMessage
public class PicTextMessage : Message { /// <summary> /// 模板静态字段 /// </summary> private static string m_Template; /// <summary> /// 默认构造函数 /// </summary> public PicTextMessage() { this.MsgType = "news"; } /// <summary> /// 从xml数据加载文本消息 /// </summary> /// <param name="xml"></param> public static PicTextMessage LoadFromXml(string xml) { PicTextMessage tm = null; if (!string.IsNullOrEmpty(xml)) { XElement element = XElement.Parse(xml); if (element != null) { tm = new PicTextMessage(); tm.FromUserName = element.Element(CommonWeiXin.FROM_USERNAME).Value; tm.ToUserName = element.Element(CommonWeiXin.TO_USERNAME).Value; tm.CreateTime = element.Element(CommonWeiXin.CREATE_TIME).Value; } } return tm; } /// <summary> /// 模板 /// </summary> public override string Template { get { if (string.IsNullOrEmpty(m_Template)) { LoadTemplate(); } return m_Template; } } /// <summary> /// 生成内容 /// </summary> /// <returns></returns> public override string GenerateContent() { this.CreateTime = CommonWeiXin.GetNowTime(); string str= string.Format(this.Template, this.ToUserName, this.FromUserName, this.CreateTime); return str; } /// <summary> /// 加载模板 /// </summary> private static void LoadTemplate() { m_Template= @"<xml> <ToUserName><![CDATA[{0}]]></ToUserName> <FromUserName><![CDATA[{1}]]></FromUserName> <CreateTime>{2}</CreateTime> <MsgType><![CDATA[news]]></MsgType> <ArticleCount>1</ArticleCount> <Articles> <item> <Title><![CDATA[有位停车欢迎你！]]></Title> <Description><![CDATA[如有问题请致电400-6238-136或直接在微信留言，我们将第一时间为您服务!]]></Description> <PicUrl><![CDATA[http://www.baidu.com/youwei.jpg]]></PicUrl> <Url><![CDATA[http://www.baidu.com]]></Url> </item> </Articles> </xml> "; } }
最后我们的效果如下所示；
本人能力有限，希望大家多多包涵.
