.NET开发微信公众号：消息处理实例
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，没法帮您埃";
}
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；
以上所述就是本文的全部内容了，希望大家能够喜欢
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