/Senparc.Weixin.MP/Senparc.Weixin.MP/RequestMessageFactory.cs

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Xml;



namespace Senparc.Weixin.MP

{

    using System.Xml.Linq;

    using Senparc.Weixin.MP.Entities;

    using Senparc.Weixin.MP.Helpers;



    public static class RequestMessageFactory

    {

        //<?xml version="1.0" encoding="utf-8"?>

        //<xml>

        //  <ToUserName><![CDATA[gh_a96a4a619366]]></ToUserName>

        //  <FromUserName><![CDATA[olPjZjsXuQPJoV0HlruZkNzKc91E]]></FromUserName>

        //  <CreateTime>1357986928</CreateTime>

        //  <MsgType><![CDATA[text]]></MsgType>

        //  <Content><![CDATA[中文]]></Content>

        //  <MsgId>5832509444155992350</MsgId>

        //</xml>



        /// <summary>

        /// 获取XDocument转换后的IRequestMessageBase实例。

        /// 如果MsgType不存在，抛出UnknownRequestMsgTypeException异常

        /// </summary>

        /// <returns></returns>

        public static IRequestMessageBase GetRequestEntity(XDocument doc)

        {

            RequestMessageBase requestMessage = null;

            RequestMsgType msgType;

            try

            {

                msgType = MsgTypeHelper.GetRequestMsgType(doc);

                switch (msgType)

                {

                    case RequestMsgType.Text:

                        requestMessage = new RequestMessageText();

                        break;

                    case RequestMsgType.Location:

                        requestMessage = new RequestMessageLocation();

                        break;

                    case RequestMsgType.Image:

                        requestMessage = new RequestMessageImage();

                        break;

                    case RequestMsgType.Voice:

                        requestMessage = new RequestMessageVoice();

                        break;

                    case RequestMsgType.Link:

                        requestMessage = new RequestMessageLink();

                        break;

                    case RequestMsgType.Event:

                        //判断Event类型

                        switch (doc.Root.Element("Event").Value.ToUpper())

                        {

                            case "ENTER"://进入会话

                                requestMessage = new RequestMessageEvent_Enter();

                                break;

                            case "LOCATION"://地理位置

                                requestMessage = new RequestMessageEvent_Location();

                                break;

                            case "SUBSCRIBE"://订阅（关注）

                                requestMessage = new RequestMessageEvent_Subscribe();

                                break;

                            case "UNSUBSCRIBE"://取消订阅（关注）

                                requestMessage = new RequestMessageEvent_Unsubscribe();

                                break;

                            default://其他意外类型（也可以选择抛出异常）

                                requestMessage = new RequestMessageEventBase();

                                break;

                        }

                        break;

                    default:

                        throw new UnknownRequestMsgTypeException(string.Format("MsgType：{0} 在RequestMessageFactory中没有对应的处理程序！", msgType), new ArgumentOutOfRangeException());//为了能够对类型变动最大程度容错（如微信目前还可以对公众账号suscribe等未知类型，但API没有开放），建议在使用的时候catch这个异常

                }

                EntityHelper.FillEntityWithXml(requestMessage, doc);

            }

            catch (ArgumentException ex)

            {

                throw new WeixinException(string.Format("RequestMessage转换出错！可能是MsgType不存在！，XML：{0}", doc.ToString()), ex);

            }

            return requestMessage;

        }





        /// <summary>

        /// 获取XDocument转换后的IRequestMessageBase实例。

        /// 如果MsgType不存在，抛出UnknownRequestMsgTypeException异常

        /// </summary>

        /// <returns></returns>

        public static IRequestMessageBase GetRequestEntity(string xml)

        {

            return GetRequestEntity(XDocument.Parse(xml));

        }





        /// <summary>

        /// 获取XDocument转换后的IRequestMessageBase实例。

        /// 如果MsgType不存在，抛出UnknownRequestMsgTypeException异常

        /// </summary>

        /// <param name="stream">如Request.InputStream</param>

        /// <returns></returns>

        public static IRequestMessageBase GetRequestEntity(Stream stream)

        {

            using (XmlReader xr = XmlReader.Create(stream))

            {

                var doc = XDocument.Load(xr);

                return GetRequestEntity(doc);

            }

        }

    }

}