微信开发第七篇发送素材（图文）信息

最近产品经理要做每天推送图文信息的功能，哎，还要超链接传递不同的参数，苦逼呀。。网上查了一些资料，下面讲解一下群发素材

要群发素材，首先要先获得素材，素材都是以图片和文字的形式推送给用户的，所以要首先获得图片和文字

微信的上传媒体接口：https://api.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE

可以用来上传图片，上传成功返回：{"type":"TYPE","media_id":"MEDIA_ID","created_at":123456789}，其中media_id就是图片在微信服务器的标识。

上传方法：

       ///

        /// 上传媒体返回媒体ID
        ///

        public static string UploadMedia(string access_token, string type, string path)
        {
            // 设置参数
            string url = string.Format("http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token={0}&type={1}", access_token, type);
            return HttpRequestUtil.HttpUploadFile(url, path);
        }

第二步：拼接图文消息素材Json字符串，其中msg就是上述的微信服务器传回来的媒体ID

       ///

        /// 拼接图文消息素材Json字符串
        ///

        public static string GetArticlesJsonStr(string access_token,string msg)
        {
            StringBuilder sbArticlesJson = new StringBuilder();

             sbArticlesJson.Append("{\"articles\":[");
                //string media_id = Tools.GetJsonValue(msg, "media_id");
               // string media_id = (msg,"media_id");
                sbArticlesJson.Append("{");
                // sbArticlesJson.Append();
                sbArticlesJson.Append("\"thumb_media_id\":\"" + msg + "\",");
                sbArticlesJson.Append("\"author\":\"" + "王华涛" + "\",");
                sbArticlesJson.Append("\"title\":\"" + "作业已经完成" + "\",");
                sbArticlesJson.Append("\"content_source_url\":\"" + "http://。。。。" + "\",");
                sbArticlesJson.Append("\"content\":\"" + "作业信息" + "\",");
                sbArticlesJson.Append("\"digest\":\"" +"您孩子的作业已经完成" + "\",");
                sbArticlesJson.Append("\"show_cover_pic\":\"1\"}");
                sbArticlesJson.Append("]}");

            return sbArticlesJson.ToString();
        } 

第三步：上传图文消息素材,其中postData就是拼接图文消息素材Json字符串，调用微信接口上传之后获得media_id

        ///

        /// 上传图文消息素材返回media_id
        ///

        public static string UploadNews(string access_token, string postData)
        {
            return HttpRequestUtil.PostUrl(string.Format("https://api.weixin.qq.com/cgi-bin/media/uploadnews?access_token={0}", access_token), postData);
        }

第四步：图文消息json,添加发送用户openid

      ///

        /// 图文消息json
        ///

        public static string CreateNewsJson(string media_id, List openids)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("{\"touser\":[\"");

            foreach（string  openid in openids）    

            {

                 sb.Append(openid);
                sb.Append("\",\"");

            }
            sb.Append("\"],");
            sb.Append("\"msgtype\":\"mpnews\",");
            sb.Append("\"mpnews\":{\"media_id\":\"" + media_id + "\"}");
            sb.Append("}");
            return sb.ToString();
        }
第五步：调用微信发送素材接口，根据OpenID列表群发素材信息

        ///

        /// 根据OpenID列表群发
        ///

        public static string Send(string access_token, string postData)
        {
            return HttpRequestUtil.PostUrl(string.Format("https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token={0}", access_token), postData);
        }