本文讲述使用Senparc.Weixin框架来快速处理各种接收事件推送。这里的消息指的是传统的微信公众平台消息交互，微信用户向公众号发送消息后，公众号回复消息给微信用户。包括以下类型：
1 subscribe/unsubscribe: 关注/取消关注事件
2 scan: 扫描带参数二维码事件
3 location: 上报地理位置事件
4 click: 自定义菜单事件
1) click: 点击菜单拉取消息时的事件推送
2) view: 点击菜单跳转链接时的事件推送
3) scancode_push：扫码推事件的事件推送
4) scancode_waitmsg：扫码推事件且弹出“消息接收中”提示框的事件推送
5) pic_sysphoto：弹出系统拍照发图的事件推送
6) pic_photo_or_album：弹出拍照或者相册发图的事件推送
7) pic_weixin：弹出微信相册发图器的事件推送
8) location_select：弹出地理位置选择器的事件推送
实现非常简单，自定义一个继承MessageHandler的类，重写这些类型的方法即可。注意：DefaultResponseMessage必须重写，用于返回没有处理过的消息类型（也可以用于默认消息，如帮助信息等）；其中所有原OnXX的抽象方法已经都改为虚方法，可以不必每个都重写。若不重写，默认返回DefaultResponseMessage方法中的结果。
下面详细介绍实现步骤：
1. 添加index页面
private readonly string Token = ConfigurationManager.AppSettings["token"];//与微信公众账号后台的Token设置保持一致，区分大小写。
protected void Page_Load(object sender, EventArgs e)
{
string signature = Request["signature"];
string timestamp = Request["timestamp"];
string nonce = Request["nonce"];
string echostr = Request["echostr"];
if (Request.HttpMethod == "GET")
{
//get method - 仅在微信后台填写URL验证时触发
if (CheckSignature.Check(signature, timestamp, nonce, Token))
{
WriteContent(echostr); //返回随机字符串则表示验证通过
}
else
{
WriteContent("failed:" + signature + "," + CheckSignature.GetSignature(timestamp, nonce, Token) + "。" +
"如果你在浏览器中看到这句话，说明此地址可以被作为微信公众账号后台的Url，请注意保持Token一致。");
}
Response.End();
}
else
{
//post method - 当有用户想公众账号发送消息时触发
if (!CheckSignature.Check(signature, timestamp, nonce, Token))
{
WriteContent("参数错误！");
return;
}
//设置每个人上下文消息储存的最大数量，防止内存占用过多，如果该参数小于等于0，则不限制
var maxRecordCount = 10;
//自定义MessageHandler，对微信请求的详细判断操作都在这里面。
var messageHandler = new CustomMessageHandler(Request.InputStream, maxRecordCount);
try
{
//测试时可开启此记录，帮助跟踪数据，使用前请确保App_Data文件夹存在，且有读写权限。
messageHandler.RequestDocument.Save(
Server.MapPath("~/App_Data/" + DateTime.Now.Ticks + "_Request_" +
messageHandler.RequestMessage.FromUserName + ".txt"));
//执行微信处理过程
messageHandler.Execute();
//测试时可开启，帮助跟踪数据
messageHandler.ResponseDocument.Save(
Server.MapPath("~/App_Data/" + DateTime.Now.Ticks + "_Response_" +
messageHandler.ResponseMessage.ToUserName + ".txt"));
WriteContent(messageHandler.ResponseDocument.ToString());
return;
}
catch (Exception ex)
{
//将程序运行中发生的错误记录到App_Data文件夹
using (TextWriter tw = new StreamWriter(Server.MapPath("~/App_Data/Error_" + DateTime.Now.Ticks + ".txt")))
{
tw.WriteLine(ex.Message);
tw.WriteLine(ex.InnerException.Message);
if (messageHandler.ResponseDocument != null)
{
tw.WriteLine(messageHandler.ResponseDocument.ToString());
}
tw.Flush();
tw.Close();
}
WriteContent("");
}
finally
{
Response.End();
}
}
}
private void WriteContent(string str)
{
Response.Output.Write(str);
}
1）当Get请求时，调用 CheckSignature.Check(signature, timestamp, nonce, Token) 方法验证url接入， 详情参考 用c#开发微信（1）服务号的服务器配置和企业号的回调模式 - url接入 （源码下载）
2) 当有Post请求过来时，调用自定义MessageHandler类，对微信请求的详细判断操作都在这里面。
var messageHandler = new CustomMessageHandler(Request.InputStream, maxRecordCount);
messageHandler.Execute();
2. 自定义消息处理类
定义CustomMessageHandler继承MessageHandler<MessageContext<IRequestMessageBase, IResponseMessageBase>>
public partial class CustomMessageHandler : MessageHandler<MessageContext<IRequestMessageBase, IResponseMessageBase>>
{
public CustomMessageHandler(Stream inputStream, int maxRecordCount = 0)
: base(inputStream, null, maxRecordCount)
{
WeixinContext.ExpireMinutes = 3;
}
public override void OnExecuting()
{
//测试MessageContext.StorageData
if (CurrentMessageContext.StorageData == null)
{
CurrentMessageContext.StorageData = 0;
}
base.OnExecuting();
}
public override void OnExecuted()
{
base.OnExecuted();
CurrentMessageContext.StorageData = ((int)CurrentMessageContext.StorageData) + 1;
}
}
3. 分别重写几种接收事件推送
我们可以通过重写MessageHandler里的这几种类型方法来处理我们的业务，当然也可以只重写需要的部分类型，不需要的类型可以不重写，只需要定义一个统一的DefaultResponseMessage
public override IResponseMessageBase DefaultResponseMessage(IRequestMessageBase requestMessage)
{
//所有没有被处理的消息会默认返回这里的结果
var responseMessage = this.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "这条消息来自DefaultResponseMessage。";
return responseMessage;
}
下面分别就这几种类型，各写一个例子：
1） 关注事件
/// <summary>
/// 订阅（关注）事件
/// </summary>
/// <returns></returns>
public override IResponseMessageBase OnEvent_SubscribeRequest(RequestMessageEvent_Subscribe requestMessage)
{
var responseMessage = ResponseMessageBase.CreateFromRequestMessage<ResponseMessageText>(requestMessage);
responseMessage.Content = GetWelcomeInfo();
return responseMessage;
}
2） 取消关注事件
/// <summary>
/// 退订
/// 实际上用户无法收到非订阅账号的消息，所以这里可以随便写。
/// unsubscribe事件的意义在于及时删除网站应用中已经记录的OpenID绑定，消除冗余数据。并且关注用户流失的情况。
/// </summary>
/// <returns></returns>
public override IResponseMessageBase OnEvent_UnsubscribeRequest(RequestMessageEvent_Unsubscribe requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "有空再来";
return responseMessage;
}
3） 扫描带参数二维码事件
public override IResponseMessageBase OnEvent_ScanRequest(RequestMessageEvent_Scan requestMessage)
{
//通过扫描关注
var responseMessage = CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "通过扫描关注。";
return responseMessage;
}
4） 上报地理位置事件
public override IResponseMessageBase OnEvent_LocationRequest(RequestMessageEvent_Location requestMessage)
{
//这里是微信客户端（通过微信服务器）自动发送过来的位置信息
var responseMessage = CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "这里写什么都无所谓，比如：上帝爱你！";
return responseMessage;//这里也可以返回null（需要注意写日志时候null的问题）
}
4. 自定义菜单事件推送
用户点击自定义菜单后，微信会把点击事件推送给开发者，请注意，点击菜单弹出子菜单，不会产生上报。请注意，第3个到第8个的所有事件，仅支持微信iPhone5.4.1以上版本，和Android5.4以上版本的微信用户，旧版本微信用户点击后将没有回应，开发者也不能正常接收到事件推送。
1） 点击菜单拉取消息时的事件推送
public override IResponseMessageBase OnTextOrEventRequest(RequestMessageText requestMessage)
{
// 预处理文字或事件类型请求。
// 这个请求是一个比较特殊的请求，通常用于统一处理来自文字或菜单按钮的同一个执行逻辑，
// 会在执行OnTextRequest或OnEventRequest之前触发，具有以下一些特征：
// 1、如果返回null，则继续执行OnTextRequest或OnEventRequest
// 2、如果返回不为null，则终止执行OnTextRequest或OnEventRequest，返回最终ResponseMessage
// 3、如果是事件，则会将RequestMessageEvent自动转为RequestMessageText类型，其中RequestMessageText.Content就是RequestMessageEvent.EventKey
if (requestMessage.Content == "OneClick")
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
strongResponseMessage.Content = "您点击了底部按钮。\r\n为了测试微信软件换行bug的应对措施，这里做了一个——\r\n换行";
return strongResponseMessage;
}
return null;//返回null，则继续执行OnTextRequest或OnEventRequest
}
public override IResponseMessageBase OnEvent_ClickRequest(RequestMessageEvent_Click requestMessage)
{
IResponseMessageBase reponseMessage = null;
//菜单点击，需要跟创建菜单时的Key匹配
switch (requestMessage.EventKey)
{
case "OneClick":
{
//这个过程实际已经在OnTextOrEventRequest中完成，这里不会执行到。
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Content = "您点击了底部按钮。\r\n为了测试微信软件换行bug的应对措施，这里做了一个——\r\n换行";
}
break;
case "SubClickRoot_Text":
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Content = "您点击了子菜单按钮。";
}
break;
case "SubClickRoot_News":
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageNews>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Articles.Add(new Article()
{
Title = "您点击了子菜单图文按钮",
Description = "您点击了子菜单图文按钮，这是一条图文信息。",
PicUrl = "http://weixin.senparc.com/Images/qrcode.jpg",
Url = "http://weixin.senparc.com"
});
}
break;
case "SubClickRoot_Music":
{
//上传缩略图
var accessToken = CommonAPIs.AccessTokenContainer.TryGetToken(appId, appSecret);
var uploadResult = AdvancedAPIs.Media.MediaApi.UploadTemporaryMedia(accessToken, UploadMediaFileType.thumb,
Server.GetMapPath("~/Images/Logo.jpg"));
//设置音乐信息
var strongResponseMessage = CreateResponseMessage<ResponseMessageMusic>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Music.Title = "天籁之音";
strongResponseMessage.Music.Description = "真的是天籁之音";
strongResponseMessage.Music.MusicUrl = "http://weixin.senparc.com/Content/music1.mp3";
strongResponseMessage.Music.HQMusicUrl = "http://weixin.senparc.com/Content/music1.mp3";
strongResponseMessage.Music.ThumbMediaId = uploadResult.thumb_media_id;
}
break;
case "SubClickRoot_Image":
{
//上传图片
var accessToken = CommonAPIs.AccessTokenContainer.TryGetToken(appId, appSecret);
var uploadResult = AdvancedAPIs.Media.MediaApi.UploadTemporaryMedia(accessToken, UploadMediaFileType.image,
Server.GetMapPath("~/Images/Logo.jpg"));
//设置图片信息
var strongResponseMessage = CreateResponseMessage<ResponseMessageImage>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Image.MediaId = uploadResult.media_id;
}
break;
case "SubClickRoot_Agent"://代理消息
{
//获取返回的XML
DateTime dt1 = DateTime.Now;
reponseMessage = MessageAgent.RequestResponseMessage(this, agentUrl, agentToken, RequestDocument.ToString());
//上面的方法也可以使用扩展方法：this.RequestResponseMessage(this,agentUrl, agentToken, RequestDocument.ToString());
DateTime dt2 = DateTime.Now;
if (reponseMessage is ResponseMessageNews)
{
(reponseMessage as ResponseMessageNews)
.Articles[0]
.Description += string.Format("\r\n\r\n代理过程总耗时：{0}毫秒", (dt2 - dt1).Milliseconds);
}
}
break;
case "Member"://托管代理会员信息
{
//原始方法为：MessageAgent.RequestXml(this,agentUrl, agentToken, RequestDocument.ToString());//获取返回的XML
reponseMessage = this.RequestResponseMessage(agentUrl, agentToken, RequestDocument.ToString());
}
break;
case "OAuth"://OAuth授权测试
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageNews>();
strongResponseMessage.Articles.Add(new Article()
{
Title = "OAuth2.0测试",
Description = "点击【查看全文】进入授权页面。\r\n注意：此页面仅供测试（是专门的一个临时测试账号的授权，并非Senparc.Weixin.MP SDK官方账号，所以如果授权后出现错误页面数正常情况），测试号随时可能过期。请将此DEMO部署到您自己的服务器上，并使用自己的appid和secret。",
Url = "http://weixin.senparc.com/oauth2",
PicUrl = "http://weixin.senparc.com/Images/qrcode.jpg"
});
reponseMessage = strongResponseMessage;
}
break;
case "Description":
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
strongResponseMessage.Content = GetWelcomeInfo();
reponseMessage = strongResponseMessage;
}
break;
case "SubClickRoot_PicPhotoOrAlbum":
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Content = "您点击了【微信拍照】按钮。系统将会弹出拍照或者相册发图。";
}
break;
case "SubClickRoot_ScancodePush":
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
reponseMessage = strongResponseMessage;
strongResponseMessage.Content = "您点击了【微信扫码】按钮。";
}
break;
default:
{
var strongResponseMessage = CreateResponseMessage<ResponseMessageText>();
strongResponseMessage.Content = "您点击了按钮，EventKey：" + requestMessage.EventKey;
reponseMessage = strongResponseMessage;
}
break;
}
return reponseMessage;
}
2） 点击菜单跳转链接时的事件推送
public override IResponseMessageBase OnEvent_ViewRequest(RequestMessageEvent_View requestMessage)
{
//说明：这条消息只作为接收，下面的responseMessage到达不了客户端，类似OnEvent_UnsubscribeRequest
var responseMessage = CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "您点击了view按钮，将打开网页：" + requestMessage.EventKey;
return responseMessage;
}
3） 扫码推事件的事件推送
/// <summary>
/// 事件之扫码推事件(scancode_push)
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_ScancodePushRequest(RequestMessageEvent_Scancode_Push requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之扫码推事件";
return responseMessage;
}
4) 扫码推事件且弹出“消息接收中”提示框的事件推送
/// <summary>
/// 事件之扫码推事件且弹出“消息接收中”提示框(scancode_waitmsg)
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_ScancodeWaitmsgRequest(RequestMessageEvent_Scancode_Waitmsg requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之扫码推事件且弹出“消息接收中”提示框";
return responseMessage;
}
5) 弹出系统拍照发图的事件推送
/// <summary>
/// 事件之弹出系统拍照发图(pic_sysphoto)
/// 实际测试时发现微信并没有推送RequestMessageEvent_Pic_Sysphoto消息，只能接收到用户在微信中发送的图片消息。
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_PicSysphotoRequest(RequestMessageEvent_Pic_Sysphoto requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之弹出系统拍照发图";
return responseMessage;
}
6) 弹出拍照或者相册发图的事件推送
/// <summary>
/// 事件之弹出拍照或者相册发图（pic_photo_or_album）
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_PicPhotoOrAlbumRequest(RequestMessageEvent_Pic_Photo_Or_Album requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之弹出拍照或者相册发图";
return responseMessage;
}
7) 弹出微信相册发图器的事件推送
/// <summary>
/// 事件之弹出微信相册发图器(pic_weixin)
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_PicWeixinRequest(RequestMessageEvent_Pic_Weixin requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之弹出微信相册发图器";
return responseMessage;
}
8) 弹出地理位置选择器的事件推送
/// <summary>
/// 事件之弹出地理位置选择器（location_select）
/// </summary>
/// <param name="requestMessage"></param>
/// <returns></returns>
public override IResponseMessageBase OnEvent_LocationSelectRequest(RequestMessageEvent_Location_Select requestMessage)
{
var responseMessage = base.CreateResponseMessage<ResponseMessageText>();
responseMessage.Content = "事件之弹出地理位置选择器";
return responseMessage;
}
5. 最后发布到自己的服务器上，可以尝试给公众号发送各种接收事件，验证公众号回复的内容
6. 源码
最后整个程序结构如下：
这里的CustomMessageHandler_Events.cs和CustomMessageHandler.cs是同一个类CustomMessageHandler; 一个处理事件，一个处理消息。
源码下载： http://yunpan.cn/cwKCaYahyczTF 访问密码 336e
同样的，使用源码前，要先把配置文件里的参数修改成自己的公众号。
关注事件效果图：
