一.前言
微信公眾平台的消息處理還是比較完善的，有最基本的文本消息，到圖文消息，到圖片消息，語音消息，視頻消息，音樂消息其基本原理都是一樣的，只不過所post的xml數據有所差別，在處理消息之前，我們要認真閱讀，官方給我們的文檔：http://mp.weixin.qq.com/wiki/14/89b871b5466b19b3efa4ada8e577d45e.html。首先我們從最基本的文本消息處理開始。
<xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName> <CreateTime>12345678</CreateTime> <MsgType><![CDATA[text]]></MsgType> <Content><![CDATA[你好]]></Content> </xml>
我們可以看到這是消息處理的一個最基本的模式，有發送者，接受者，創建時間，類型，內容等等。
首先我們來創建一個消息處理的類，這個類用來捕獲，所有的消息請求，根據不同的消息請求類型來處理不同的消息回復。
public class WeiXinService
{
/// <summary>
/// TOKEN
/// </summary>
private const string TOKEN = "finder";
/// <summary>
/// 簽名
/// </summary>
private const string SIGNATURE = "signature";
/// <summary>
/// 時間戳
/// </summary>
private const string TIMESTAMP = "timestamp";
/// <summary>
/// 隨機數
/// </summary>
private const string NONCE = "nonce";
/// <summary>
/// 隨機字符串
/// </summary>
private const string ECHOSTR = "echostr";
/// <summary>
///
/// </summary>
private HttpRequest Request { get; set; }
/// <summary>
/// 構造函數
/// </summary>
/// <param name="request"></param>
public WeiXinService(HttpRequest request)
{
this.Request = request;
}
/// <summary>
/// 處理請求，產生響應
/// </summary>
/// <returns></returns>
public string Response()
{
string method = Request.HttpMethod.ToUpper();
//驗證簽名
if (method == "GET")
{
if (CheckSignature())
{
return Request.QueryString[ECHOSTR];
}
else
{
return "error";
}
}
//處理消息
if (method == "POST")
{
return ResponseMsg();
}
else
{
return "無法處理";
}
}
/// <summary>
/// 處理請求
/// </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>
/// 檢查簽名
/// </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);
//驗證
if (new_signature == signature)
{
return true;
}
else
{
return false;
}
}
}
在來看看我們的首先是如何捕獲消息的。首頁Default.ashx的代碼如下
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/html";
string postString = string.Empty;
if (HttpContext.Current.Request.HttpMethod.ToUpper() == "POST")
{
//由微信服務接收請求，具體處理請求
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();
}
}
}
從上面的代碼中我們可以看到WeiXinService.cs類中的消息相應至關重要。
/// <summary>
/// 處理請求
/// </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是一個消息處理接口，其下面有EventHandler，TextHandler處理類實現這個接口。代碼如下
/// <summary>
/// 處理接口
/// </summary>
public interface IHandler
{
/// <summary>
/// 處理請求
/// </summary>
/// <returns></returns>
string HandleRequest();
}
EventHandler
class EventHandler : IHandler
{
/// <summary>
/// 請求的xml
/// </summary>
private string RequestXml { get; set; }
/// <summary>
/// 構造函數
/// </summary>
/// <param name="requestXml"></param>
public EventHandler(string requestXml)
{
this.RequestXml = requestXml;
}
/// <summary>
/// 處理請求
/// </summary>
/// <returns></returns>
public string HandleRequest()
{
string response = string.Empty;
EventMessage em = EventMessage.LoadFromXml(RequestXml);
if (em.Event.Equals("subscribe", StringComparison.OrdinalIgnoreCase))//用來判斷是不是首次關注
{
PicTextMessage tm = new PicTextMessage();//我自己創建的一個圖文消息處理類
tm.ToUserName = em.FromUserName;
tm.FromUserName = em.ToUserName;
tm.CreateTime = CommonWeiXin.GetNowTime();
response = tm.GenerateContent();
}
return response;
}
}
TextHandler
/// <summary>
/// 文本信息處理類
/// </summary>
public class TextHandler : IHandler
{
string openid { get; set; }
string access_token { get; set; }
/// <summary>
/// 請求的XML
/// </summary>
private string RequestXml { get; set; }
/// <summary>
/// 構造函數
/// </summary>
/// <param name="requestXml">請求的xml</param>
public TextHandler(string requestXml)
{
this.RequestXml = requestXml;
}
/// <summary>
/// 處理請求
/// </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 = "您什麼都沒輸入，沒法幫您啊。";
}
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;
//進行發送者、接收者轉換
string temp = tm.ToUserName;
tm.ToUserName = tm.FromUserName;
tm.FromUserName = temp;
response = tm.GenerateContent();
return response;
}
/// <summary>
/// 處理其他消息
/// </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"))//用來匹配用戶輸入的關鍵字
{
response = "你的Openid: "+openid;
}
else if (requestContent.Contains("token") || requestContent.Contains("access_token"))
{
response = "你的access_token: " + access_token;
}else
{
response = "試試其他關鍵字吧。";
}
return response;
}
}
HandlerFactory
/// <summary>
/// 處理器工廠類
/// </summary>
public class HandlerFactory
{
/// <summary>
/// 創建處理器
/// </summary>
/// <param name="requestXml">請求的xml</param>
/// <returns>IHandler對象</returns>
public static IHandler CreateHandler(string requestXml)
{
IHandler handler = null;
if (!string.IsNullOrEmpty(requestXml))
{
//解析數據
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;
}
}
在這裡基本的一些類已經完成了，現在我們來完成，關注我們的微信公眾號，我們就發送一條圖文消息，同時輸入我們的一些關鍵字，返回一些消息，比如輸入id返回用戶的openid等等。
二.PicTextMessage
public class PicTextMessage : Message
{
/// <summary>
/// 模板靜態字段
/// </summary>
private static string m_Template;
/// <summary>
/// 默認構造函數
/// </summary>
public PicTextMessage()
{
this.MsgType = "news";
}
/// <summary>
/// 從xml數據加載文本消息
/// </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>
/// 生成內容
/// </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>
/// 加載模板
/// </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[有位停車歡迎你！]]></Title>
<Description><![CDATA[如有問題請致電400-6238-136或直接在微信留言，我們將第一時間為您服務!]]></Description>
<PicUrl><![CDATA[http://www.baidu.com/youwei.jpg]]></PicUrl>
<Url><![CDATA[http://www.baidu.com]]></Url>
</item>
</Articles>
</xml> ";
}
}
最後我們的效果如下所示；
以上所述就是本文的全部內容了，希望大家能夠喜歡
