实例：用C#.NET手把手教你做微信公众号开发（13）--事件消息处理之取消关注

一、取消关注事件

用户在取消关注公众号时，微信会把这个事件推送到开发者填写的URL，方便开发者做帐号的解绑等处理。

  
  
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二、代码实现

本篇比较简单，所以直接上代码了。

在接收到微信服务器发来的事件之后，首先由指定的接口网页AccessWx.aspx对事件类型进行判别，然后交给指定的事件处理类处理和回应。在本系列文章第1篇介绍的AccessWx.aspx.cs中开始部分引入命名空间using QinMing.Weixin.EventHandlerUnSubscribe;

并完善下面处理unsubscribe这一段，增加本篇给出的关注事件处理环节。  
 

else if(MsgType == "event")  
{
	string Event = xn.SelectSingleNode("//Event").InnerText;
	if(Event == "subscribe")
	{
		//对用户关注公众号的事件处理，使用QinMing.Weixin.EventHandlerSubscribe命名空间下的SubscribeEventDeal类
		SubscribeEventDeal ued = new SubscribeEventDeal();
		Response.Write(ued.DealResult(weixinXML));	
	}
	else if(Event == "unsubscribe")
	{
		//对用户取消关注公众号的事件处理，使用QinMing.Weixin.EventHandlerUnSubscribe命名空间下的UnSubscribeEventDeal类
		UnSubscribeEventDeal ued = new UnSubscribeEventDeal();
		Response.Write(ued.DealResult(weixinXML));	
	}
	//其它处理
}

在命名空间QinMing.Weixin.EventHandlerUnSubscribe下新建一个类UnSubscribeEventDeal，用来处理微信服务器发来的取消关注事件消息。记得类源码文件要放在App_Code目录下！下面是关注事件消息处理源码：
QinMingWeixinEventHandlerUnSubscribe.cs文件内容如下：
 

using System;
using System.Web;
using System.Xml;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using System.Net;
using System.Threading;
using System.Threading.Tasks;
using QinMing.Config;
using QinMing.Tools;
using QinMing.Tools.DB;
using QinMing.Weixin.ReturnContent;
using QinMing.WeixinUserInfo;
using QinMing.WeixinPayPayment;

namespace QinMing.Weixin.EventHandlerUnSubscribe
{
	//事件消息处理：取消关注公众号
    public class UnSubscribeEventDeal :System.Web.UI.Page
    {

		public string DealResult(string weixinXML)
        {
            string content = DealSubscribe(weixinXML);  
            return content;
        }

        public string DealSubscribe(string weixinXML)
        {
            string content1="";
            string strresponse = "";
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(weixinXML);
            XmlNodeList list = doc.GetElementsByTagName("xml");
            XmlNode xn = list[0];
            string FromUserName = xn.SelectSingleNode("//FromUserName").InnerText;   //关注用户的加密后openid
            string ToUserName = xn.SelectSingleNode("//ToUserName").InnerText;       //公众微信号原始ID
            string MsgType=xn.SelectSingleNode("//MsgType").InnerText;
            string Event=xn.SelectSingleNode("//Event").InnerText;
			string EventKey = xn.SelectSingleNode("//EventKey").InnerText;
            
			DealLeave(FromUserName);
			
			SaveEvent(FromUserName, ToUserName);
			
            //给管理员发送粉丝取消关注通知
			QinMing.WeixinTemplateMessage.SendTemplateMessage.SendRemindMsg("管理员openid", "粉丝取消关注提醒" + FromUserName, "http://www.yourweb.com/Weixin/DisplayUser.aspx?open_id=" + FromUserName);  
			
			return strresponse;
        }
		
        //记录粉丝取关公众号时的相关信息
		public void DealLeave(string FromUserName)
        {
            string strConn = QinMingConfig.DatabaseConnStr;
            SqlConnection conn = new SqlConnection(strConn);
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "insert into weixin_leave_log (open_id,leave_time) values('" + FromUserName + "',getdate())";
            cmd.ExecuteScalar();
            cmd.CommandText = "update weixin_join_log set remove_flag=1 where remove_flag=0 and open_id='" + FromUserName + "'";
            cmd.ExecuteScalar();
            cmd.CommandText = "update weixin_user_info set remove_flag = '已取关' where open_id = '" + FromUserName + "'";
            cmd.ExecuteScalar();
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
                conn.Dispose();
            }
        }
		
		//保存事件信息。
        public void SaveEvent(string FromUserName, string ToUserName)
        {
            SqlConnection conn = new SqlConnection(QinMingConfig.DatabaseConnStr);
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "insert into weixin_recv_event (msg_type,event_type,open_id,gh_id,recv_time) "
			    + "values ('event','unsubscribe','" + FromUserName + "','" + ToUserName + "',getdate()) ";
            //QinMingTools.WriteLog("sql语句：", cmd.CommandText);
			cmd.ExecuteScalar();
      
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
                conn.Dispose();
            }
        }

    }
}