调用群发接口没问题，返回数据中有media_id，然后使用这个id群发，或预览时返回的数据都是44003 图文消息为空，最主要是预览文本也是一样的返回值！ 贴代码如下

Wxapi.UpLoadInfo info = Wxapi.WeiXinHelper.WxUpLoad(@"d:\1.jpg", AccessToken.Instance.Access_Token, MediaType.image);   // 调用图片上传接口上传图片获取media_id
             // 拼接群发json
            StringBuilder sbArticlesJson = new StringBuilder();
            sbArticlesJson.Append("{"articles":[");
            sbArticlesJson.Append("{");
            sbArticlesJson.Append(""thumb_media_id":"" + info.media_id + "",");
            sbArticlesJson.Append(""author":"" + "dark_yx"+ "",");
            sbArticlesJson.Append(""title":"" + "title" + "",");
            sbArticlesJson.Append(""content_source_url":"" +"http://baidu.com"+ "",");
            sbArticlesJson.Append(""content":"" +"测试数据\b加\b" + "",");
            sbArticlesJson.Append(""digest":"" + "测试"+ "",");
            sbArticlesJson.Append(""show_cover_pic":"1"}");
            sbArticlesJson.Append("]}");
            // 这里的result是获取到media_id的
            string result = Wxapi.HttpClientHelper.PostResponse(Wxapi.WeiXinConst.WeiXin_Article_Url, sbArticlesJson.ToString());
            // 调试使用的openid
            string openid = "oYq5_juOqEXEesH_Sb4gNFSj6xZU";
            // 拼接预览json
            string articleid = Wxapi.JsonHelp.GetJsonValue(result, "media_id");
            StringBuilder testJson = new StringBuilder();
            testJson.Append("{"touser":"" + openid + "", ");
            testJson.Append(""mpnews":{ ");
            testJson.Append(""media_id":"" + articleid + """);
            testJson.Append("}, "msgtype":"mpnews"}");
            
             // 这里的result就是44003
            string result2 = Wxapi.HttpClientHelper.PostResponse(Wxapi.WeiXinConst.WeiXin_Article_Url, testJson.ToString());