前言
微信公众号的开发，园子里有很多资料，这里简述。
虽说是智能，现在是仿佛智障，很多是hard code逻辑，日后将逐步加入LUIS,现在一些常用的打招呼（你好，您好，hi，hey，hello，how are you等识别比较好）。
业务性的处理，更多是逻辑上，比如常用的回复1,2,3,4然后返回对应的消息。这里涉及多轮会话，要求对上文的记忆，不然容易回答串题了。
还有就是一些分词技术，这个目前对空格敏感，还有就是南京市长江大桥，是南京市长，还是长江大桥？这个是日后话题了。
.NET Core APIi的方式，创建一个WeChat API Controller
验证微信服务器地址的方法：
[HttpGet]
[Route("api/wechat")]
public IActionResult Get(string signature, string timestamp, string nonce, string echostr)
{
var token = ConfigReader.TokenStr;//微信公众平台后台设置的Token
if (string.IsNullOrEmpty(token))
{
return NotFound("请先设置Token！");
//return new HttpResponseMessage() { Content = new StringContent("请先设置Token！", Encoding.GetEncoding("UTF-8"), "application/x-www-form-urlencoded") };
}
var ent = "";
if (!BasicAPI.CheckSignature(signature, timestamp, nonce, token, out ent))
{
return NotFound("验证微信签名失败！");
//return new HttpResponseMessage() { Content = new StringContent("参数错误！", Encoding.GetEncoding("UTF-8"), "application/x-www-form-urlencoded") };
}
//返回随机字符串则表示验证通过
return Ok(echostr);
//return new HttpResponseMessage() { Content = new StringContent(echostr, Encoding.GetEncoding("UTF-8"), "application/x-www-form-urlencoded") };
}
验证成功之后，所有消息，微信会转到这个方法：
用户发送消息后，微信平台自动Post一个请求到这里，并等待响应XML。
[HttpPost]
[Route("api/wechat")]
public async Task<IActionResult> Post()
{
WeChatMessage message = null;
string signature = HttpContext.Request.Query["signature"].ToString();
string timestamp = HttpContext.Request.Query["timestamp"].ToString();
string nonce = HttpContext.Request.Query["nonce"].ToString();
string echostr = HttpContext.Request.Query["echostr"].ToString();
var safeMode = HttpContext.Request.Query["encrypt_type"].ToString() == "aes";
using (var streamReader = new StreamReader(HttpContext.Request.Body, Encoding.UTF8))
{
var decryptMsg = string.Empty;
var msg = streamReader.ReadToEnd();
#region 解密
if (safeMode)
{
var msg_signature = HttpContext.Request.Query["msg_signature"];
var wechatBizMsgCrypt = new WeChatMsgCrypt(ConfigReader.TokenUrl, ConfigReader.EncodingAESKey, ConfigReader.AppId);
var ret = wechatBizMsgCrypt.DecryptMsg(msg_signature, timestamp, nonce, msg, ref decryptMsg);
if (ret != 0)//解密失败
{
//TODO：失败的业务处理逻辑
}
}
else
{
decryptMsg = msg;
}
#endregion
message = ParseMessageType.Parse(decryptMsg);
}
var response = await new WeChatExecutor(repo).Execute(message);
var encryptMsg = string.Empty;
#region 加密
if (safeMode)
{
var msg_signature = HttpContext.Request.Query["msg_signature"];
var wxBizMsgCrypt = new WeChatMsgCrypt(ConfigReader.TokenUrl, ConfigReader.EncodingAESKey, ConfigReader.AppId);
var ret = wxBizMsgCrypt.EncryptMsg(response, timestamp, nonce, ref encryptMsg);
if (ret != 0)//加密失败
{
//TODO：开发者加密失败的业务处理逻辑
}
}
else
{
encryptMsg = response;
}
#endregion
return Ok(encryptMsg);
//return new HttpResponseMessage()
//{
// Content = new StringContent(encryptMsg, Encoding.GetEncoding("UTF-8"), "application/x-www-form-urlencoded")
// //ContentType = "text/xml",
//};
}
将接收到的消息，转发到Bot(Microsoft BotFramework)服务，将Bot服务的SecretKey配置上：
public async static Task<string> PostMessage(string message, string openId)
{
HttpClient client;
HttpResponseMessage response;
bool IsReplyReceived = false;
string ReceivedString = null;
client = new HttpClient();
client.BaseAddress = new Uri("https://directline.botframework.com/api/conversations/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//bot-int WeChat channel
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("BotConnector", ConfigReader.BotSecretKey);
response = await client.GetAsync("/api/tokens/");
if (response.IsSuccessStatusCode)
{
var conversation = new Conversation();
response = await client.PostAsJsonAsync("/api/conversations/", conversation);
if (response.IsSuccessStatusCode)
{
Conversation ConversationInfo = response.Content.ReadAsAsync(typeof(Conversation)).Result as Conversation;
var contentString = response.Content.ReadAsStringAsync();
string conversationUrl = ConversationInfo.conversationId + "/messages/";
Message msg = new Message() { text = message, from = openId, channelData = "WeChat" };
response = await client.PostAsJsonAsync(conversationUrl, msg);
if (response.IsSuccessStatusCode)
{
response = await client.GetAsync(conversationUrl);
if (response.IsSuccessStatusCode)
{
MessageSet BotMessage = response.Content.ReadAsAsync(typeof(MessageSet)).Result as MessageSet;
ReceivedString = BotMessage.messages[1].text;
IsReplyReceived = true;
}
}
}
}
return ReceivedString;
}
这里要定义几个model，用于序列化Bot返回的数据类型：
public class Conversation
{
public string conversationId { get; set; }
public string token { get; set; }
public int expires_in { get; set; }
}
public class MessageSet
{
public Message[] messages { get; set; }
public string watermark { get; set; }
public string eTag { get; set; }
}
public class Message
{
public string id { get; set; }
public string conversationId { get; set; }
public DateTime created { get; set; }
public string from { get; set; }
public string text { get; set; }
public string channelData { get; set; }
public string[] images { get; set; }
public Attachment[] attachments { get; set; }
public string eTag { get; set; }
}
public class Attachment
{
public string url { get; set; }
public string contentType { get; set; }
}
Bot server中的消息路由处理方法
public virtual async Task<HttpResponseMessage> Post([FromBody] Activity activity)
{
if (activity != null && activity.GetActivityType() == ActivityTypes.Message)
{
logger.Information(new ConversationEvent
{
EventType = LogEventType.ChatBotActivity,
Message = $"ChatBot message controller receives a message, content: {activity.Text}",
Activity = activity
});
var isAgent = await ServiceManager.AgentManager.IsAgent(activity.From.Id);
var context = await ServiceManager.ContextManager.GetUserContext(activity, isAgent);
var activityLogger = new Logger.CosmosDbActivityLogger();
if (await ServiceManager.CommandMessageHandler.HandleCommandAsync(activity, isAgent) == false)
{
if (!string.IsNullOrEmpty(activity.Text)
&& activity.Text.ToLower().Contains(CommandRequestConnection))
{
var contextManager = ServiceManager.ContextManager;
var messageRouterResultHandler = ServiceManager.MessageRouterResultHandler;
var result = await contextManager.RequestConnection(context, activity);
await activityLogger.LogAsync(activity);
// Handle the result, if required
await messageRouterResultHandler.HandleResultAsync(result);
}
else
{
if (isAgent)
{
IAgentActor agentActor = SFHelper.GetActor<IAgentActor>(activity);
await activityLogger.LogAsync(activity);
await agentActor.MessagePost(context, new ActivityDataContract(activity));
}
else
{
ICustomerActor customerActor = SFHelper.GetActor<ICustomerActor>(activity);
await customerActor.MessagePost(context, new ActivityDataContract(activity));
if (activity.Text.Equals("没有解决") || activity.Text.Equals("解决了"))
{
await ServiceManager.InquiryManager.CloseInquiryAsync(context);
}
}
}
}
}
else
{
HandleSystemMessage(activity);
}
return new HttpResponseMessage(HttpStatusCode.Accepted);
}
定义回复消息内容，markdown格式，微信支持不友好。
public static Activity BuildProactiveGreeting(Activity context)
{
var responseMessage = context.CreateReply();
// TODO: Move to MenuManager via DataReposotry to persist to CosmosDB
var topLevelMenuItems = new List<CardActionItem>
{
new CardActionItem() { Title = "技术支持", ActionType = ActionTypes.ImBack },
new CardActionItem() { Title = "账单/订阅/配额支持", ActionType = ActionTypes.ImBack },
new CardActionItem() { Title = "产品咨询", ActionType = ActionTypes.ImBack },
new CardActionItem() { Title = "注册问题", ActionType = ActionTypes.ImBack }
};
// TODO: make sure we get correct name from wechat channel
string cardTitleText = "Hi，我是您的智能客服，等您很久啦~猜您可能对以下内容感兴趣：";
var heroCard = BuildHeroCardWithActionButtons(cardTitleText, topLevelMenuItems);
responseMessage.AttachmentLayout = AttachmentLayoutTypes.List;
responseMessage.Attachments = new List<Attachment>() { heroCard.ToAttachment() };
return responseMessage;
}
Bot回复消息：
var client = new ConnectorClient(new Uri(message.ServiceUrl), new MicrosoftAppCredentials());
var reply = GreetingHelper.BuildProactiveGreeting(message);
client.Conversations.ReplyToActivityAsync(reply);
效果图
就是打招呼的时候，会回复一个简单得产品介绍，暂时没有多轮会话，因为上下文理解出现一些问题，就不献丑了（滑稽）。
后记
日后还有个切换到人工客服，当输入人工客服时，调用微信公众号的客服消息接口，每两小时（过期时间7200s）获取一次token，
然后根据用户的OPENID，将微信支持的消息格式，发送到粉丝端，获取token的IP必须添加到白名单中。
这个要求公众号是认证的，个人的没有授权。