google gcm single push notification to multiple android devices using .net

Create default.aspx page

Notification Message label_Result

Source Code (C#)

using System;

using System.Collections.Generic;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

using System.IO;

using System.Linq;

using System.Net;

using System.Text;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

public partial class OneMessagetoMultipleDevices : System.Web.UI.Page

{

    List<Noti_Tabs> Regids = new List<Noti_Tabs>();

    string[] stringregIds;

   

    protected void Page_Load(object sender, EventArgs e)

    {

        lbl1.Text = "";

        lbl_regIds.Text = "";

    }

    protected void btn_Send_Click(object sender, EventArgs e)

    {

            SqlConnection con = new SqlConnection("Database Connection from Sql Server");

            SqlCommand cmd = new SqlCommand(" select RegIds from Table", con);

            SqlDataAdapter da = new SqlDataAdapter(cmd);

            DataSet ds = new DataSet();

            da.Fill(ds);

            if (ds.Tables[0].Rows.Count > 0)

            {

                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)

                {

                    Regids.Add(new Noti_Tabs { RegId = ds.Tables[0].Rows[i]["RegIds"].ToString() });

                }

                foreach (Noti_Tabs reg in Regids)

                {

                    lbl_regIds.Text += reg.RegId + "\",\"";

                }

                lbl_regIds.Text = lbl_regIds.Text.TrimEnd('"', ',', '"');

               

                var applicationID = "AIzaS--------------------------uH0itc";   
                // applicationID means google Api key 

                var SENDER_ID = "123-----006"; 
                // SENDER_ID is nothing but your ProjectID (from API Console- google code) 

                var value = txtBox_Msg.Text.Replace("\t",string.Empty) ;
                // Text box message                                                                             

               

                WebRequest tRequest;

                tRequest = WebRequest.Create("https://android.googleapis.com/gcm/send");

                tRequest.Method = "post";

                tRequest.ContentType = " application/json";

                tRequest.Headers.Add(string.Format("Authorization: key={0}", applicationID));

                tRequest.Headers.Add(string.Format("Sender: id={0}", SENDER_ID));

                string postData = "{\"collapse_key\":\"score_update\",\"time_to_live\":108,\"delay_while_idle\":true,\"data\": { \"message\" : " + "\"" + value + "\",\"time\": " + "\"" + System.DateTime.Now.ToString() + "\"},\"registration_ids\":[\"" + lbl_regIds.Text + "\"]}";

                Console.WriteLine(postData);

                Byte[] byteArray = Encoding.UTF8.GetBytes(postData);

                tRequest.ContentLength = byteArray.Length;

                Stream dataStream = tRequest.GetRequestStream();

                dataStream.Write(byteArray, 0, byteArray.Length);

                dataStream.Close();

                WebResponse tResponse = tRequest.GetResponse();

                dataStream = tResponse.GetResponseStream();

                StreamReader tReader = new StreamReader(dataStream);

                String sResponseFromServer = tReader.ReadToEnd();   //Get response from GCM server.

                lbl_Response.Text = sResponseFromServer;      //Assigning GCM response to Label text

                tReader.Close();

                dataStream.Close();

                tResponse.Close();

            }

        }

}

Add Class

public class Noti_Tabs

{

    public string RegId { get; set; }

}