微信公众平台向特定用户推送消息

一、首先需要将微信的openid与系统用户绑定。

在用户关注公众平台的时候，回复一个链接，要求用户绑定，可以设计如下消息进行回复，（openid最好进行加密处理，后者还需要用这个字段绑定fakeid）。

欢迎关注有问必答平台,<a href='http://myweixin123.duapp.com/bind.html?openid=@openid'>点击此处进行用户绑定</a>!

在bind.html页面将openid与系统的usercode进行绑定，这个绑定过程非常简单，这里不详叙述。

二、将openid与fakeid进行绑定

微信公众平台是一回一答的模式；但是在微信公众平台后台，可以向特定用户进行消息发送。我们利用这个机制使用代码去模拟这个过程来实现消息推送。

首先需要模拟登录：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Security.Cryptography;

using System.Text;

using System.Net;

using System.IO;

using System.Security.Authentication;

using System.Security.Cryptography.X509Certificates;

/// <summary>

///WeiXinLogin 的摘要说明

/// </summary>

public class WeiXinLogin

{

    

    /// <summary>

    /// MD5　32位加密

    /// </summary>

    /// <param name="str"></param>

    /// <returns></returns>

    static string GetMd5Str32(string str)

    {

        MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();

        // Convert the input string to a byte array and compute the hash. 

        char[] temp = str.ToCharArray();

        byte[] buf = new byte[temp.Length];

        for (int i = 0; i < temp.Length; i++)

        {

            buf[i] = (byte)temp[i];

        }

        byte[] data = md5Hasher.ComputeHash(buf);

        // Create a new Stringbuilder to collect the bytes 

        // and create a string. 

        StringBuilder sBuilder = new StringBuilder();

        // Loop through each byte of the hashed data  

        // and format each one as a hexadecimal string. 

        for (int i = 0; i < data.Length; i++)

        {

            sBuilder.Append(data[i].ToString("x2"));

        }

        // Return the hexadecimal string. 

        return sBuilder.ToString();

    }

 

    public static bool ExecLogin(string name,string pass)

    {

        bool result = false;

        string password = GetMd5Str32(pass).ToUpper();

        string padata = "username=" + name + "&pwd=" + password + "&imgcode=&f=json";

        string url = "https://mp.weixin.qq.com/cgi-bin/login?lang=zh_CN ";//请求登录的URL

        try

        {

            CookieContainer cc = new CookieContainer();//接收缓存

            byte[] byteArray = Encoding.UTF8.GetBytes(padata); // 转化

            HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(url);  //新建一个WebRequest对象用来请求或者响应url

            ServicePointManager.CertificatePolicy = new AcceptAllCertificatePolicy();

 

            webRequest2.CookieContainer = cc;                                      //保存cookie 

            webRequest2.Method = "POST";                                          //请求方式是POST

            webRequest2.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.69 Safari/537.36";

            webRequest2.Referer = "https://mp.weixin.qq.com/";

            webRequest2.ContentType = "application/x-www-form-urlencoded";       //请求的内容格式为application/x-www-form-urlencoded

            webRequest2.ContentLength = byteArray.Length;

            Stream newStream = webRequest2.GetRequestStream();           //返回用于将数据写入 Internet 资源的 Stream。

            // Send the data.

            newStream.Write(byteArray, 0, byteArray.Length);    //写入参数

            newStream.Close();

            HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();

            StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.Default);

            string text2 = sr2.ReadToEnd();

 

            //此处用到了newtonsoft来序列化

            WeiXinRetInfo retinfo = Newtonsoft.Json.JsonConvert.DeserializeObject<WeiXinRetInfo>(text2);

            string token = string.Empty;

            if (retinfo.ErrMsg.Length > 0)

            {

                token = retinfo.ErrMsg.Split(new char[] { '&' })[2].Split(new char[] { '=' })[1].ToString();//取得令牌

                LoginInfo.LoginCookie = cc;

                LoginInfo.CreateDate = DateTime.Now;

                LoginInfo.Token = token;

                result = true;

            }

        }

        catch (Exception ex)

        {

           

            throw new Exception(ex.StackTrace);

        }

        return result;

    }

 

    public static class LoginInfo

    {

        /// <summary>

        /// 登录后得到的令牌

        /// </summary>       

        public static string Token { get; set; }

        /// <summary>

        /// 登录后得到的cookie

        /// </summary>

        public static CookieContainer LoginCookie { get; set; }

        /// <summary>

        /// 创建时间

        /// </summary>

        public static DateTime CreateDate { get; set; }

 

    }

    internal class AcceptAllCertificatePolicy : ICertificatePolicy

    {

        public AcceptAllCertificatePolicy()

        {

        }

 

        public bool CheckValidationResult(ServicePoint sPoint,

           X509Certificate cert, WebRequest wRequest, int certProb)

        {

            // Always accept 

            return true;

        }

    } 

}

获取fakeid

public static ArrayList SubscribeMP()

{

 

    try

    {

        CookieContainer cookie = null;

        string token = null;

 

 

        cookie = WeiXinLogin.LoginInfo.LoginCookie;//取得cookie

        token = WeiXinLogin.LoginInfo.Token;//取得token

 

        /*获取用户信息的url，这里有几个参数给大家讲一下，1.token此参数为上面的token 2.pagesize此参数为每一页显示的记录条数

 

        3.pageid为当前的页数，4.groupid为微信公众平台的用户分组的组id，当然这也是我的猜想不一定正确*/

        string Url = "https://mp.weixin.qq.com/cgi-bin/contactmanage?t=user/index&pagesize=10&pageidx=0&type=0&groupid=0&token=" + token + "&lang=zh_CN";

        HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(Url);

        webRequest2.CookieContainer = cookie;

        webRequest2.ContentType = "text/html; charset=UTF-8";

        webRequest2.Method = "GET";

        webRequest2.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1";

        webRequest2.ContentType = "application/x-www-form-urlencoded";

        HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();

        StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.Default);

        string text2 = sr2.ReadToEnd();

 

 

        MatchCollection mc;

 

        //由于此方法获取过来的信息是一个html网页所以此处使用了正则表达式，注意：（此正则表达式只是获取了fakeid的信息如果想获得一些其他的信息修改此处的正则表达式就可以了。）

        Regex r = new Regex(""id"\:\d+,"nick_name""); //定义一个Regex对象实例

        mc = r.Matches(text2);

        Int32 friendSum = mc.Count;          //好友总数

 

        string fackID = "";

 

        ArrayList fackID1 = new ArrayList();

 

        for (int i = 0; i < friendSum; i++)

        {

            //"id":208989515,"nick_name"

            fackID = mc[i].Value.Replace(","nick_name"", "").Split(new char[] { ':' })[1];

            fackID = fackID.Replace(""", "").Trim();

            fackID1.Add(fackID);

        }

 

        return fackID1;

 

 

 

    }

    catch (Exception ex)

    {

        throw new Exception(ex.StackTrace);

    }

}

根据fakeid获取openid

    public static string GetOpenidByFakeid(string fakeid)
    {
        try
        {
            CookieContainer cookie = null;
            string token = null;


            cookie = WeiXinLogin.LoginInfo.LoginCookie;//取得cookie
            token = WeiXinLogin.LoginInfo.Token;//取得token
            string Url = "https://mp.weixin.qq.com/cgi-bin/singlemsgpage?msgid=&source=&count=20&t=wxm-singlechat&fromfakeid=" + fakeid + "&token=" + token + "&lang=zh_CN";
            HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(Url);
            webRequest2.CookieContainer = cookie;
            webRequest2.ContentType = "text/html; charset=UTF-8";
            webRequest2.Method = "GET";
            webRequest2.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1";
            webRequest2.ContentType = "application/x-www-form-urlencoded";
            HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();
            StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.UTF8);
            string text2 = sr2.ReadToEnd();
            HtmlDocument doc = new HtmlDocument();
            doc.LoadHtml(text2);
            var str = doc.GetElementbyId("json-msgList").InnerHtml;
            JArray messages = JArray.Parse(str);
            foreach (var message in messages)
            {
                string strContent = HttpUtility.HtmlDecode(message["content"].ToString());
                Regex reg = new Regex(@"(?is)<a[^>]*?href=(['""s]?)(?<href>[^'""s]*)1[^>]*?>");
                MatchCollection match = reg.Matches(strContent);
                var href = "";
                foreach (Match m in match)
                {
                    href = m.Groups["href"].Value;
                }

                var openid = GetUrlParamValue(href, "openid");
                if (!string.IsNullOrEmpty(openid))
                 return openid;

            }
            return "";
        }
        catch (Exception ex)
        {
            return "";
        }
  
    }

由于之前有建立openid与usercode的关系，所以可以根据usercode找到openid，又可以根据openid找到fakeid。使用下面代码进行推送：

public static bool SendMessage(string Message, string fakeid)

{

    bool result = false;

    CookieContainer cookie = null;

    string token = null;

    cookie = WeiXinLogin.LoginInfo.LoginCookie;//取得cookie

    token =  WeiXinLogin.LoginInfo.Token;//取得token

 

    string strMsg = System.Web.HttpUtility.UrlEncode(Message);  //对传递过来的信息进行url编码

    string padate = "type=1&content=" + strMsg + "&error=false&tofakeid=" + fakeid + "&token=" + token + "&ajax=1";

    string url = "https://mp.weixin.qq.com/cgi-bin/singlesend?t=ajax-response&lang=zh_CN";

 

    byte[] byteArray = Encoding.UTF8.GetBytes(padate); // 转化

 

    HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(url);

 

    webRequest2.CookieContainer = cookie; //登录时得到的缓存

 

    webRequest2.Referer = "https://mp.weixin.qq.com/cgi-bin/singlemsgpage?token=" + token + "&fromfakeid=" + fakeid + "&msgid=&source=&count=20&t=wxm-singlechat&lang=zh_CN";

 

    webRequest2.Method = "POST";

 

    webRequest2.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1";

 

    webRequest2.ContentType = "application/x-www-form-urlencoded";

 

    webRequest2.ContentLength = byteArray.Length;

 

    Stream newStream = webRequest2.GetRequestStream();

 

    // Send the data.           

    newStream.Write(byteArray, 0, byteArray.Length);    //写入参数   

 

    newStream.Close();

 

    HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();

 

    StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.Default);

 

    string text2 = sr2.ReadToEnd();

    if (text2.Contains("ok"))

    {

        result = true;

    }

    return result;

}

　　

可以写一个长期运行的windows服务用于建立fakeid和openid的关系，这里不再详诉。