asp.net WeChat development (advanced mass text)

This article mainly introduces the relevant content of advanced mass text messaging in asp.net WeChat development. Friends who need it can refer to it

First of all, let’s explain the process of mass text messaging. I personally developed The program must first have a UI before you can start writing code. The interface is as follows,

Looking at the picture, we can also see that first we need to obtain This WeChat account can also send several messages in groups this month. As for how to calculate, if a message is successfully sent in a group, a message will be stored in the local database to calculate the number of messages (I believe this can be done). If more than 4 messages are sent, it cannot be sent ( I have already restricted it here, because the service account can only send 4 messages per month, and it is useless to send more. The user can only receive 4 messages, unless the preview function is used to send them one by one, but the preview function can only send 100 times. Maybe you can use the developer mode to send group messages N times more, because after I sent the group message twice, I went to the backend of the WeChat public platform official website and saw that I could still send 4 messages in a group, which was a bit depressing), the target of the group message! You can choose to all users or group users, and to save the number of group messages, I will not test group text messages here. Please refer to the following code for details:

Bind the remaining number of group messages this month

 /// <summary> 
 /// 绑定本月剩余群发条数
 /// </summary>
 private void BindMassCount()
 {
 WxMassService wms = new WxMassService();
 List<WxMassInfo> wxmaslist = wms.GetMonthMassCount();
 //官方微信服务号每月只能群发4条信息，（订阅号每天1条）多余信息，将不会成功推送，这里已经设定为4
 this.lbMassCounts.Text = (4 - int.Parse(wxmaslist.Count.ToString())).ToString();

 if (wxmaslist.Count >= 4)
 {
 this.LinkBtnSubSend.Enabled = false;
 this.LinkBtnSubSend.Attributes.Add("Onclick", "return confirm(&#39;群发信息已达上限！请下月初再试！&#39;)");
 }
 else
 {
 this.LinkBtnSubSend.Enabled = true;
 this.LinkBtnSubSend.Attributes.Add("Onclick", "return confirm(&#39;您确定要群发此条信息？？&#39;)");
 }
 }

Binding group list

 /// <summary>
 /// 绑定分组列表
 /// </summary>
 private void BindGroupList()
 {
 WeiXinServer wxs = new WeiXinServer();

 ///从缓存读取accesstoken
 string Access_token = Cache["Access_token"] as string;

 if (Access_token == null)
 {
 //如果为空，重新获取
 Access_token = wxs.GetAccessToken();

 //设置缓存的数据7000秒后过期
 Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
 }

 string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);

 string jsonres = "";

 string content = Cache["AllGroups_content"] as string;

 if (content == null)
 {
 jsonres = "https://api.weixin.qq.com/cgi-bin/groups/get?access_token=" + Access_tokento;

 HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(jsonres);
 myRequest.Method = "GET";
 HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
 StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8);
 content = reader.ReadToEnd();
 reader.Close();

 //设置缓存的数据7000秒后过期
 Cache.Insert("AllGroups_content", content, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
 }

 //使用前需要引用Newtonsoft.json.dll文件
 JObject jsonObj = JObject.Parse(content);


 int groupsnum = jsonObj["groups"].Count();

 this.DDLGroupList.Items.Clear();//清除

 for (int i = 0; i < groupsnum; i++)
 {
 this.DDLGroupList.Items.Add(new ListItem(jsonObj["groups"][i]["name"].ToString() + "(" + jsonObj["groups"][i]["count"].ToString() + ")", jsonObj["groups"][i]["id"].ToString()));
 }
 }
 /// <summary>
 /// 选择群发对象类型，显示隐藏分组列表项
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 protected void DDLMassType_SelectedIndexChanged(object sender, EventArgs e)
 {
 if (int.Parse(this.DDLMassType.SelectedValue.ToString()) > 0)
 {
 this.DDLGroupList.Visible = true;
 }
 else
 {
  this.DDLGroupList.Visible = false;
 }
 }

群发

#

 /// <summary>
 /// 群发
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 protected void LinkBtnSubSend_Click(object sender, EventArgs e)
 {
 //根据单选按钮判断类型，发送
 ///如果选择的是文本消息
 if (this.RadioBtnList.SelectedValue.ToString().Equals("0"))
 {
 if (String.IsNullOrWhiteSpace(this.txtwenben.InnerText.ToString().Trim()))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请输入您要群发文本内容！&#39;);", true);
  return;
 }
 if (this.txtwenben.InnerText.ToString().Trim().Length<10)
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;文本内容至少需要10个字符以上！&#39;);", true);
  return;
 }

 WxMassService wms = new WxMassService();
 List<WxMassInfo> wxmaslist = wms.GetMonthMassCount();

 if (wxmaslist.Count >= 4)
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;本月可群发消息数量已达上限！&#39;);", true);
  return;
 }
 else
 {


  //如何群发类型为全部用户，根据openID列表群发给全部用户，订阅号不可用，服务号认证后可用
  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
  StringBuilder sbs = new StringBuilder();
  sbs.Append(GetAllUserOpenIDList());

  WeiXinServer wxs = new WeiXinServer();

  ///从缓存读取accesstoken
  string Access_token = Cache["Access_token"] as string;

  if (Access_token == null)
  {
  //如果为空，重新获取
  Access_token = wxs.GetAccessToken();

  //设置缓存的数据7000秒后过期
  Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
  }

  string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);


  string posturl = "https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token=" + Access_tokento;

  ///群发POST数据示例如下： 
  //  {
  // "touser":[
  // "OPENID1",
  // "OPENID2"
  // ],
  // "msgtype": "text",
  // "text": { "content": "hello from boxer."}
  //}

  string postData = "{\"touser\":[" + sbs.ToString() +
  "],\"msgtype\":\"text\",\"text\":{\"content\":\"" + this.txtwenben.InnerText.ToString() +
  "\"}";


  string tuwenres = wxs.GetPage(posturl, postData);

  //使用前需药引用Newtonsoft.json.dll文件
  JObject jsonObj = JObject.Parse(tuwenres);

  if (jsonObj["errcode"].ToString().Equals("0"))
  {
   //群发成功后，保存记录
  WxMassInfo wmi = new WxMassInfo();

  wmi.ImageUrl = "";
  wmi.type = "文本";
  wmi.contents = this.txtwenben.InnerText.ToString().Trim();
  wmi.title = this.txtwenben.InnerText.ToString().Substring(0, 10) + "...";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
  wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
  wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID


  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
  Session["wmninfo"] = null;
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
  return;
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
  return;
  }
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务提交失败！！&#39;);", true);
  return;
  }
  }
  else
  {
  string group_id = this.DDLGroupList.SelectedValue.ToString();


  WeiXinServer wxs = new WeiXinServer();

  ///从缓存读取accesstoken
  string Access_token = Cache["Access_token"] as string;

  if (Access_token == null)
  {
  //如果为空，重新获取
  Access_token = wxs.GetAccessToken();

  //设置缓存的数据7000秒后过期
  Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
  }

  string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);


  string posturl = "https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token=" + Access_tokento;

  ///群发POST数据示例如下： 
  // {
  // "filter":{
  // "is_to_all":false
  // "group_id":"2"
  // },
  // "text":{
  // "content":"CONTENT"
  // },
  // "msgtype":"text"
  //}
  //}

  string postData = "{\"filter\":{\"is_to_all\":\"false\"\"group_id\":\"" + group_id +
  "\"},\"text\":{\"content\":\"" + this.txtwenben.InnerText.ToString() +
  "\"},\"msgtype\":\"text\"}";


  string tuwenres = wxs.GetPage(posturl, postData);

  //使用前需药引用Newtonsoft.json.dll文件
  JObject jsonObj = JObject.Parse(tuwenres);

  if (jsonObj["errcode"].ToString().Equals("0"))
  {
  //群发成功后，保存记录
  WxMassInfo wmi = new WxMassInfo();

  wmi.ImageUrl = "";
  wmi.type = "文本";
  wmi.contents = this.txtwenben.InnerText.ToString().Trim();
  wmi.title = this.txtwenben.InnerText.ToString().Substring(0, 10) + "...";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
  wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
  wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID


  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
  Session["wmninfo"] = null;
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
  return;
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
  return;
  }
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务提交失败！！&#39;);", true);
  return;
  }
  }

 
 }
 }
 //如果选择的是图文消息
 if (this.RadioBtnList.SelectedValue.ToString().Equals("1"))
 {
 if (String.IsNullOrWhiteSpace(this.lbtuwenmedai_id.Text.ToString().Trim()))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请选择或新建图文素材再进行群发！&#39;);", true);
  return;
 }

 WxMassService wms = new WxMassService();

 List<WxMassInfo> wxmaslist = wms.GetMonthMassCount();

 if (wxmaslist.Count >= 4)
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;本月可群发消息数量已达上限！&#39;);", true);
  return;
 }
 else
 {
  
  //如何群发类型为全部用户，根据openID列表群发给全部用户，订阅号不可用，服务号认证后可用
  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
  StringBuilder sbs = new StringBuilder();
  sbs.Append(GetAllUserOpenIDList());

  WeiXinServer wxs = new WeiXinServer();

  ///从缓存读取accesstoken
  string Access_token = Cache["Access_token"] as string;

  if (Access_token == null)
  {
  //如果为空，重新获取
  Access_token = wxs.GetAccessToken();

  //设置缓存的数据7000秒后过期
  Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
  }

  string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);


  string posturl = "https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token=" + Access_tokento;

  ///群发POST数据示例如下： 
  // {
  // "touser":[
  // "OPENID1",
  // "OPENID2"
  // ],
  // "mpnews":{
  // "media_id":"123dsdajkasd231jhksad"
  // },
  // "msgtype":"mpnews"
  //}

  string postData = "{\"touser\":[" + sbs.ToString() +
  "],\"mpnews\":{\"media_id\":\"" + this.lbtuwenmedai_id.Text.ToString() +
  "\"},\"msgtype\":\"mpnews\"}";


  string tuwenres = wxs.GetPage(posturl, postData);

  //使用前需药引用Newtonsoft.json.dll文件
  JObject jsonObj = JObject.Parse(tuwenres);

  if (jsonObj["errcode"].ToString().Equals("0"))
  {
  Session["media_id"] = null;
  WxMassInfo wmi = new WxMassInfo();
  if (Session["wmninfo"] != null)
  {
  WxMpNewsInfo wmninfo = Session["wmninfo"] as WxMpNewsInfo;

  wmi.title = wmninfo.title.ToString();
  wmi.contents = wmninfo.contents.ToString();
  wmi.ImageUrl = wmninfo.ImageUrl.ToString();


  wmi.type = "图文";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
   wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
   wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID

  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
   Session["wmninfo"] = null;
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
   return;
  }
  else
  {
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
   return;
  }
  }
  else
  {
  wmi.title = "";
  wmi.contents = "";
  wmi.ImageUrl = "";
  wmi.type = "图文";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
   wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
   wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID

  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
   Session["wmninfo"] = null;
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！图文部分数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
   return;
  }
  else
  {
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
   return;
  }
  }
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务提交失败！！&#39;);", true);
  return;
  }


  }
  else
  {
  //根据分组进行群发，订阅号和服务号认证后均可用

  string group_id = this.DDLGroupList.SelectedValue.ToString();


  WeiXinServer wxs = new WeiXinServer();

  ///从缓存读取accesstoken
  string Access_token = Cache["Access_token"] as string;

  if (Access_token == null)
  {
  //如果为空，重新获取
  Access_token = wxs.GetAccessToken();

  //设置缓存的数据7000秒后过期
  Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
  }

  string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);


  string posturl = "https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token=" + Access_tokento;

  ///群发POST数据示例如下： 
  // {
  // "filter":{
  // "is_to_all":false
  // "group_id":"2"
  // },
  // "mpnews":{
  // "media_id":"123dsdajkasd231jhksad"
  // },
  // "msgtype":"mpnews"
  //}

  string postData = "{\"filter\":{\"is_to_all\":\"false\"\"group_id\":\""+group_id+
  "\"},\"mpnews\":{\"media_id\":\"" + this.lbtuwenmedai_id.Text.ToString() +
  "\"},\"msgtype\":\"mpnews\"}";


  string tuwenres = wxs.GetPage(posturl, postData);

  //使用前需药引用Newtonsoft.json.dll文件
  JObject jsonObj = JObject.Parse(tuwenres);

  if (jsonObj["errcode"].ToString().Equals("0"))
  {
  Session["media_id"] = null;
  WxMassInfo wmi = new WxMassInfo();
  if (Session["wmninfo"] != null)
  {
  WxMpNewsInfo wmninfo = Session["wmninfo"] as WxMpNewsInfo;

  wmi.title = wmninfo.title.ToString();
  wmi.contents = wmninfo.contents.ToString();
  wmi.ImageUrl = wmninfo.ImageUrl.ToString();


  wmi.type = "图文";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
   wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
   wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID

  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
   Session["wmninfo"] = null;
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
   return;
  }
  else
  {
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
   return;
  }
  }
  else
  {
  wmi.title = "";
  wmi.contents = "";
  wmi.ImageUrl = "";
  wmi.type = "图文";

  if (this.DDLMassType.SelectedValue.ToString().Equals("0"))
  {
   wmi.massObject = this.DDLMassType.SelectedItem.Text.ToString();
  }
  else
  {
   wmi.massObject = this.DDLGroupList.SelectedItem.Text.ToString();
  }

  wmi.massStatus = "成功";//群发成功之后返回的状态码
  wmi.massMessageID = jsonObj["msg_id"].ToString();//群发成功之后返回的消息ID

  wmi.massDate = System.DateTime.Now.ToString();

  int num = wms.AddWxMassInfo(wmi);

  if (num > 0)
  {
   Session["wmninfo"] = null;
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！图文部分数据已保存！&#39;);location=&#39;WxMassManage.aspx&#39;;", true);
   return;
  }
  else
  {
   ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务已提交成功！！！数据保存失败！&#39;);", true);
   return;
  }
  }
  }
  else
  {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;群发任务提交失败！！&#39;);", true);
  return;
  }
  }
 }
 }
 }

Preview before sending

/// <summary>
 /// 发送前预览
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 protected void LinkBtnSendPreview_Click(object sender, EventArgs e)
 {
 WeiXinServer wxs = new WeiXinServer();

 ///从缓存读取accesstoken
 string Access_token = Cache["Access_token"] as string;

 if (Access_token == null)
 {
 //如果为空，重新获取
 Access_token = wxs.GetAccessToken();

 //设置缓存的数据7000秒后过期
 Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
 }

 string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);


 string posturl = "https://api.weixin.qq.com/cgi-bin/message/mass/preview?access_token=" + Access_tokento;

 ///如果选择的是文本消息
 if (this.RadioBtnList.SelectedValue.ToString().Equals("0"))
 {
 if (String.IsNullOrWhiteSpace(this.txtwenben.InnerText.ToString().Trim()))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请输入您要发送预览的文本内容！&#39;);", true);
  return;
 }
 if (this.txttoUserName.Value.ToString().Trim().Equals("请输入用户微信号"))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请输入接收消息的用户微信号！&#39;);", true);
  return;
 }
 //文本消息的json数据{
 // "touser":"OPENID", 可改为对微信号预览，例如towxname：zhangsan
 // "text":{ 
 // "content":"CONTENT" 
 // }, 
 // "msgtype":"text"
 //}
 string postData = "{\"towxname\":\"" + this.txttoUserName.Value.ToString() +
   "\",\"text\":{\"content\":\"" + this.txtwenben.InnerText.ToString() +
   "\"},\"msgtype\":\"text\"}";

 string tuwenres = wxs.GetPage(posturl, postData);

 //使用前需药引用Newtonsoft.json.dll文件
 JObject jsonObj = JObject.Parse(tuwenres);

 if (jsonObj["errcode"].ToString().Equals("0"))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;发送预览成功！！&#39;);", true);
  return;
 }
 else
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;发送预览失败！！&#39;);", true);
  return;
 }
 }
 //如果选择的是图文消息
 if (this.RadioBtnList.SelectedValue.ToString().Equals("1"))
 {
 if(String.IsNullOrWhiteSpace(this.lbtuwenmedai_id.Text.ToString().Trim()))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请选择要预览的图文素材！&#39;);", true);
  return;
 }
 if (this.txttoUserName.Value.ToString().Trim().Equals("请输入用户微信号"))
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;请输入接收消息的用户微信号！&#39;);", true);
  return;
 }
 //图文消息的json数据{
 // "touser":"OPENID", 可改为对微信号预览，例如towxname：zhangsan
  // "mpnews":{ 
  // "media_id":"123dsdajkasd231jhksad" 
  // },
  // "msgtype":"mpnews" 
  //}
 string postData = "{\"towxname\":\"" + this.txttoUserName.Value.ToString() +
  "\",\"mpnews\":{\"media_id\":\"" + this.lbtuwenmedai_id.Text.ToString() +
  "\"},\"msgtype\":\"mpnews\"}";
 
 string tuwenres = wxs.GetPage(posturl, postData);

 //使用前需药引用Newtonsoft.json.dll文件
 JObject jsonObj = JObject.Parse(tuwenres);

 if (jsonObj["errcode"].ToString().Equals("0"))
 {
  Session["media_id"] = null;
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;发送预览成功！！&#39;);", true);
  return;
 }
 else
 {
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", "alert(&#39;发送预览失败！！&#39;);", true);
  return;
 }


 }
 
 }

The key part is to obtain the openIDs of all users and concatenate them into strings:

 /// <summary>
 /// 获取所有微信用户的OpenID
 /// </summary>
 /// <returns></returns>
 protected string GetAllUserOpenIDList()
 {
 StringBuilder sb = new StringBuilder();

 WeiXinServer wxs = new WeiXinServer();

 ///从缓存读取accesstoken
 string Access_token = Cache["Access_token"] as string;

 if (Access_token == null)
 {
 //如果为空，重新获取
 Access_token = wxs.GetAccessToken();

 //设置缓存的数据7000秒后过期
 Cache.Insert("Access_token", Access_token, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
 }

 string Access_tokento = Access_token.Substring(17, Access_token.Length - 37);

 string jsonres = "";

 string content = Cache["AllUserOpenList_content"] as string;

 if (content == null)
 {
 jsonres = "https://api.weixin.qq.com/cgi-bin/user/get?access_token=" + Access_tokento;

 HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(jsonres);
 myRequest.Method = "GET";
 HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
 StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8);
 content = reader.ReadToEnd();
 reader.Close();

 //设置缓存的数据7000秒后过期
 Cache.Insert("AllUserOpenList_content", content, null, DateTime.Now.AddSeconds(7000), System.Web.Caching.Cache.NoSlidingExpiration);
 }

 //使用前需要引用Newtonsoft.json.dll文件
 JObject jsonObj = JObject.Parse(content);


 if (jsonObj.ToString().Contains("count"))
 {
 int totalnum = int.Parse(jsonObj["count"].ToString());



 for (int i = 0; i < totalnum; i++)
 {
  sb.Append(&#39;"&#39;);
  sb.Append(jsonObj["data"]["openid"][i].ToString());
  sb.Append(&#39;"&#39;);
  sb.Append(",");
 }
 }

 return sb.Remove(sb.ToString().LastIndexOf(","),1).ToString();
 }

This is the end, next chapter We will continue to explain the group sending of graphic and text information. Because before sending the graphic and text information to a group, you need to upload the materials required for the graphic and text information and obtain the media_id, so this chapter will not introduce it. The next chapter will introduce how to create a single graphic and text message and send it to a group. I hope you will like.

For more asp.net WeChat development (advanced group text) related articles, please pay attention to the PHP Chinese website!