C#微信公众平台开发之高级群发接口

/// <summary>
/// Http上传文件
/// </summary>
public static string HttpUploadFile(string url,string path)
{
 // 设置参数
 HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
 CookieContainer cookieContainer = new CookieContainer();
 request.CookieContainer = cookieContainer;
 request.AllowAutoRedirect = true;
 request.Method = "POST";
 string boundary = DateTime.Now.Ticks.ToString("X"); // 随机分隔线
 request.ContentType = "multipart/form-data;charset=utf-8;boundary=" + boundary;
 byte[] itemBoundaryBytes = Encoding.UTF8.GetBytes("rn--" + boundary + "rn");
 byte[] endBoundaryBytes = Encoding.UTF8.GetBytes("rn--" + boundary + "--rn");

 int pos = path.LastIndexOf("");
 string fileName = path.Substring(pos + 1);

 //请求头部信息 
 StringBuilder sbHeader = new StringBuilder(string.Format("Content-Disposition:form-data;name="file";filename="{0}"rnContent-Type:application/octet-streamrnrn",fileName));
 byte[] postHeaderBytes = Encoding.UTF8.GetBytes(sbHeader.ToString());

 FileStream fs = new FileStream(path,FileMode.Open,FileAccess.Read);
 byte[] bArr = new byte[fs.Length];
 fs.Read(bArr,bArr.Length);
 fs.Close();

 Stream postStream = request.GetRequestStream();
 postStream.Write(itemBoundaryBytes,itemBoundaryBytes.Length);
 postStream.Write(postHeaderBytes,postHeaderBytes.Length);
 postStream.Write(bArr,bArr.Length);
 postStream.Write(endBoundaryBytes,endBoundaryBytes.Length);
 postStream.Close();

 //发送请求并获取相应回应数据
 HttpWebResponse response = request.GetResponse() as HttpWebResponse;
 //直到request.GetResponse()程序才开始向目标网页发送Post请求
 Stream instream = response.GetResponseStream();
 StreamReader sr = new StreamReader(instream,Encoding.UTF8);
 //返回结果网页（html）代码
 string content = sr.ReadToEnd();
 return content;
}

/// <summary>
/// 上传媒体返回媒体ID
/// </summary>
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);
}

string msg = WXApi.UploadMedia(access_token,"image",path); // 上图片返回媒体ID
string media_id = Tools.GetJsonValue(msg,"media_id");

/// <summary>
/// 拼接图文消息素材Json字符串
/// </summary>
public static string GetArticlesJsonStr(PageBase page,string access_token,DataTable dt)
{
 StringBuilder sbArticlesJson = new StringBuilder();

 sbArticlesJson.Append("{"articles":[");
 int i = 0;
 foreach (DataRow dr in dt.Rows)
 {
 string path = page.MapPath(dr["ImgUrl"].ToString());
 if (!File.Exists(path))
 {
  return "{"code":0,"msg":"要发送的图片不存在"}";
 }
 string msg = WXApi.UploadMedia(access_token,path); // 上图片返回媒体ID
 string media_id = Tools.GetJsonValue(msg,"media_id");
 sbArticlesJson.Append("{");
 sbArticlesJson.Append(""thumb_media_id":"" + media_id + "",");
 sbArticlesJson.Append(""author":"" + dr["Author"].ToString() + "",");
 sbArticlesJson.Append(""title":"" + dr["Title"].ToString() + "",");
 sbArticlesJson.Append(""content_source_url":"" + dr["TextUrl"].ToString() + "",");
 sbArticlesJson.Append(""content":"" + dr["Content"].ToString() + "",");
 sbArticlesJson.Append(""digest":"" + dr["Content"].ToString() + "",");
 if (i == dt.Rows.Count - 1)
 {
  sbArticlesJson.Append(""show_cover_pic":"1"}");
 }
 else
 {
  sbArticlesJson.Append(""show_cover_pic":"1"},");
 }
 i++;
 }
 sbArticlesJson.Append("]}");

 return sbArticlesJson.ToString();
}

/// <summary>
/// 请求Url，发送数据
/// </summary>
public static string PostUrl(string url,string postData)
{
 byte[] data = Encoding.UTF8.GetBytes(postData);

 // 设置参数
 HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
 CookieContainer cookieContainer = new CookieContainer();
 request.CookieContainer = cookieContainer;
 request.AllowAutoRedirect = true;
 request.Method = "POST";
 request.ContentType = "application/x-www-form-urlencoded";
 request.ContentLength = data.Length;
 Stream outstream = request.GetRequestStream();
 outstream.Write(data,data.Length);
 outstream.Close();

 //发送请求并获取相应回应数据
 HttpWebResponse response = request.GetResponse() as HttpWebResponse;
 //直到request.GetResponse()程序才开始向目标网页发送Post请求
 Stream instream = response.GetResponseStream();
 StreamReader sr = new StreamReader(instream,Encoding.UTF8);
 //返回结果网页（html）代码
 string content = sr.ReadToEnd();
 return content;
}

/// <summary>
/// 上传图文消息素材返回media_id
/// </summary>
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);
}

string articlesJson = ImgItemDal.GetArticlesJsonStr(this,dt);
string newsMsg = WXApi.UploadNews(access_token,articlesJson);
string newsid = Tools.GetJsonValue(newsMsg,"media_id");

/// <summary>
/// 获取关注者OpenID集合
/// </summary>
public static List<string> GetOpenIDs(string access_token)
{
 List<string> result = new List<string>();

 List<string> openidList = GetOpenIDs(access_token,null);
 result.AddRange(openidList);

 while (openidList.Count > 0)
 {
 openidList = GetOpenIDs(access_token,openidList[openidList.Count - 1]);
 result.AddRange(openidList);
 }

 return result;
}

/// <summary>
/// 获取关注者OpenID集合
/// </summary>
public static List<string> GetOpenIDs(string access_token,string next_openid)
{
 // 设置参数
 string url = string.Format("https://api.weixin.qq.com/cgi-bin/user/get?access_token={0}&next_openid={1}",string.IsNullOrWhiteSpace(next_openid) ? "" : next_openid);
 string returnStr = HttpRequestUtil.RequestUrl(url);
 int count = int.Parse(Tools.GetJsonValue(returnStr,"count"));
 if (count > 0)
 {
 string startFlg = ""openid":[";
 int start = returnStr.IndexOf(startFlg) + startFlg.Length;
 int end = returnStr.IndexOf("]",start);
 string openids = returnStr.Substring(start,end - start).Replace(""","");
 return openids.Split(',').ToList<string>();
 }
 else
 {
 return new List<string>();
 }
}

/// <summary>
/// 图文消息json
/// </summary>
public static string CreateNewsJson(string media_id,List<string> openidList)
{
 StringBuilder sb = new StringBuilder();
 sb.Append("{"touser":[");
 sb.Append(string.Join(",",openidList.ConvertAll<string>(a => """ + a + """).ToArray()));
 sb.Append("],");
 sb.Append(""msgtype":"mpnews",");
 sb.Append(""mpnews":{"media_id":"" + media_id + ""}");
 sb.Append("}");
 return sb.ToString();
}

resultMsg = WXApi.Send(access_token,WXMsgUtil.CreateNewsJson(newsid,openidList));


/// <summary>
/// 根据OpenID列表群发
/// </summary>
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}",postData);
}

/// <summary>
/// 群发
/// </summary>
public string Send()
{
 string type = Request["type"];
 string data = Request["data"];

 string access_token = AdminUtil.GetAccessToken(this); //获取access_token
 List<string> openidList = WXApi.GetOpenIDs(access_token); //获取关注者OpenID列表
 UserInfo loginUser = AdminUtil.GetLoginUser(this); //当前登录用户 

 string resultMsg = null;

 //发送文本
 if (type == "1")
 {
 resultMsg = WXApi.Send(access_token,WXMsgUtil.CreateTextJson(data,openidList));
 }

 //发送图片
 if (type == "2")
 {
 string path = MapPath(data);
 if (!File.Exists(path))
 {
  return "{"code":0,path);
 string media_id = Tools.GetJsonValue(msg,"media_id");
 resultMsg = WXApi.Send(access_token,WXMsgUtil.CreateImageJson(media_id,openidList));
 }

 //发送图文消息
 if (type == "3")
 {
 DataTable dt = ImgItemDal.GetImgItemTable(loginUser.OrgID,data);
 string articlesJson = ImgItemDal.GetArticlesJsonStr(this,dt);
 string newsMsg = WXApi.UploadNews(access_token,articlesJson);
 string newsid = Tools.GetJsonValue(newsMsg,openidList));
 }

 //结果处理
 if (!string.IsNullOrWhiteSpace(resultMsg))
 {
 string errcode = Tools.GetJsonValue(resultMsg,"errcode");
 string errmsg = Tools.GetJsonValue(resultMsg,"errmsg");
 if (errcode == "0")
 {
  return "{"code":1,"msg":""}";
 }
 else
 {
  return "{"code":0,"msg":"errcode:"
  + errcode + ",errmsg:"
  + errmsg + ""}";
 }
 }
 else
 {
 return "{"code":0,"msg":"type参数错误"}";
 }
}