Introduction
In this article I am going to discuss about GCM architecture and describe how to send Push Notifications to
Android Mobile. In one of my previous articles I have clearly described how to send Push Notifications to Google Chrome browser. You can view the following link:
Before this lets check what a PUSH NOTIFICATION is,
Push notification, also called server push notification, is the delivery of information from a software application to a computing device like Mobile(Android,Iphone,Windows,etc),Tablet,etc without a specific request from the client.
These Notifications looks as follow.
GCM (Google cloud Messaging) is a free service provided by Google to send messages to different clients like (Android, iPhone, Chrome, Blackberry, etc).
GCM delivers messages only when the client is online. If the client is not online the GCM stores its notification inside a Queue, later when the client comes online then the message is delivered.
For receiving Push Notification your Android Client must be above 2.2.
For sending push notifications to any client we need three steps.
- Create a new project in Google Console where the user will get SenderId and Browser Api Key.
- This SenderId will be used by the Android Mobile Developer to generate RegisterId. This registerId is unique for every mobile.
- Now the user sends the Push Notification to the GCM server using the RegisterId and BrowserApi Key.
- The GCM will send the Notification to the required Mobile.
Now, the first step is to create a project in
Google Console. Open the console and create a new project and give a new name.
After creating project copy the Project Number which is the SenderId. I have attached the screenshot here.
Now search for Google Cloud Messaging.
Click the Google Cloud Messaging for Android, iOS and Chrome and enable it.
After clicking Enable click Credentials.
Open the BrowserKey and save it.
Now copy the API key from it.
The work is finished. Now, the Android developer uses the previously created SenderId or project number to generate RegisterId.
NOTE
It is the task ofthe Aandroid developer to give you the RegisterId of the mobile using senderId. Don't waste time in searching for generating RegisterId.
You will get the RegisterId which is mentioned in Step two. Now after getting RegisterId we have to use the Register id and API key to send push notificationsto the GCM.
Here for sending messages I have designed the following UI.
Here I have attached the HTML code for this.
- <%@ Page Language="C#" AutoEventWireup="true" CodeFile="PushNotification.aspx.cs" Inherits="PushNotification" %>
-
- <!DOCTYPE html>
-
- <html xmlns="http://www.w3.org/1999/xhtml">
- <head runat="server">
- <title></title>
- </head>
- <body>
- <form id="form1" runat="server">
- <div>
- <asp:TextBox runat="server" ID="txt_message" TextMode="MultiLine" Height="124px" Width="336px"></asp:TextBox>
-
- </div>
- <div>
- <asp:Button ID="btn_send" Text="Send" runat="Server" OnClick="btn_send_Click" />
- <br />
- <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
- </div>
- </form>
- </body>
- </html>
Here is the code on button click to send Notification.
- using System;
- using System.Collections.Generic;
- using System.IO;
- using System.Linq;
- using System.Net;
- using System.Net.Security;
- using System.Security.Cryptography.X509Certificates;
- using System.Text;
- using System.Web;
- using System.Web.UI;
- using System.Web.UI.WebControls;
-
- public partial class PushNotification : System.Web.UI.Page
- {
- protected void Page_Load(object sender, EventArgs e)
- {
-
- }
- protected void btn_send_Click(object sender, EventArgs e)
- {
- //RegisterId you got from Android Developer.
- string deviceId = "XXXXXXXXXXXXXbQw:APA91bEU_CsohZ12YUXXXXXXXXXXXXXjJwzhzQGL2NIEKlri_9cfMHbehh7n2y03KO0s9EsupKT_ezRaOo13JNNm10xjRqxnE9pjCymPvV-PXb29z7doQRAnOqEawAXXXXXXXXXXXX";
-
- string message = "Demo Notification";
- string tickerText = "Patient Registration";
- string contentTitle = txt_message.Text;
- string postData =
- "{ \"registration_ids\": [ \"" + deviceId + "\" ], " +
- "\"data\": {\"tickerText\":\"" + tickerText + "\", " +
- "\"contentTitle\":\"" + contentTitle + "\", " +
- "\"message\": \"" + message + "\"}}";
-
- string response = SendGCMNotification("BrowserAPIKey", postData);
-
-
- Label1.Text = response;
-
- }
-
- private string SendGCMNotification(string apiKey, string postData, string postDataContentType = "application/json")
- {
- ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateServerCertificate);
-
-
-
- byte[] byteArray = Encoding.UTF8.GetBytes(postData);
-
-
-
- HttpWebRequest Request = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
- Request.Method = "POST";
-
-
- Request.ContentType = postDataContentType;
- Request.Headers.Add(string.Format("Authorization: key={0}", apiKey));
- Request.ContentLength = byteArray.Length;
-
- Stream dataStream = Request.GetRequestStream();
- dataStream.Write(byteArray, 0, byteArray.Length);
- dataStream.Close();
-
-
-
- try
- {
- WebResponse Response = Request.GetResponse();
-
- HttpStatusCode ResponseCode = ((HttpWebResponse)Response).StatusCode;
- if (ResponseCode.Equals(HttpStatusCode.Unauthorized) || ResponseCode.Equals(HttpStatusCode.Forbidden))
- {
- var text = "Unauthorized - need new token";
- }
- else if (!ResponseCode.Equals(HttpStatusCode.OK))
- {
- var text = "Response from web service isn't OK";
- }
-
- StreamReader Reader = new StreamReader(Response.GetResponseStream());
- string responseLine = Reader.ReadToEnd();
- Reader.Close();
-
- return responseLine;
- }
- catch (Exception e)
- {
- }
- return "error";
- }
- public static bool ValidateServerCertificate(
- object sender,
- X509Certificate certificate,
- X509Chain chain,
- SslPolicyErrors sslPolicyErrors)
- {
- return true;
- }
- }
Thus after sending it will show the following output which means the message is successfully delivered to the GCM server.
Note after sending message to the GCM server the GCM server will identify the mobile using the RegisterId and notify the message to that mobile.
To know all the parameters used in this process and other details please check the following:
Hope this code will help you to know about GCM and sending Push Notification Using GCM.
Read more articles on Android,
GCM (Google cloud Messaging) is a free service provided by Google to send messages to different clients like (Android, iPhone, Chrome, Blackberry, etc).
After clicking Enable click Credentials.
Open the BrowserKey and save it.
Now copy the API key from it.
The work is finished. Now, the Android developer uses the previously created SenderId or project number to generate RegisterId.
Dhiraj ChauhanPosted Apr 15, 2019, 2:57 AM
Response is success but i am not getting notification on my android phone
Basit KhanPosted Dec 23, 2017, 3:03 AM
Many Thanks for your article, but i want for Google chrome. When i sent push up notification i shows hard coded message. My service-worker.js file is self.addEventListener('push', function (event) { var data = {}; if (event.data) { data = event.data.json(); } var title = data.message || "Something Has Happened"; var body = 'We have received a push message !'; var icon = 'images/icon.png'; var tag = 'simple-push-demo-notification-tag'; console.log(event); event.waitUntil( self.registration.showNotification(title, { body: body, icon: 'images/icon.png', tag: tag }) ); }); with your above code when i pass the parameter the O/P postData is "{ \"registration_ids\": [ \"<GOOGLE CHROME ID>\" ], \"data\": {\"tickerText\":\"Patient Registration\", \"body\":\"heelo\", \"message\": \"Demo Notification\"}}" its fire but only showing hardcoded message which is in service-worker.js not showing in body which i passed. Thanks Basit
nithya mkPosted Dec 2, 2017, 10:52 AM
Sir, Can u upload a video of this type of project ... My need, when the asp. Net page click the button then any type changes in mobile phone...
nithya mkPosted Dec 2, 2017, 10:45 AM
Remote server show the 401 unauthorized error... & how to show the web request through message box.. Pls reply me..
Funvl VlerPosted Nov 27, 2017, 2:19 AM
The remote server returned an error: (401) Unauthorized.
Arul ManoPosted Jul 14, 2017, 3:27 AM
i got this type of error"{\"multicast_id\":6430601019766681627,\"success\":0,\"failure\":1,\"canonical_ids\":0,\"results\":[{\"error\":\"MismatchSenderId\"}]}"
Arul ManoPosted Jul 14, 2017, 3:27 AM
I got this type of error please resolve this error.
Kishor HingePosted Jul 14, 2017, 1:12 AM
The remote server returned an error: (401) Unauthorized. this error in c# code can you plz solutaion for that
Balaji MPosted Jul 11, 2017, 2:58 PM
How to get registration id to send push notification. I'm a C# developer.
vikas pagarePosted May 24, 2017, 2:53 AM
Hello sir, Above code is working properly, but can u share code using FCM for above code
piyush desaniPosted Apr 14, 2017, 2:42 AM
I have devicetoken stored into my database and want to send notification to all devicetoken which are stored into db. Can You tell me how to send notification to all on button click event in C# using fcm?
shweta singhPosted Apr 3, 2017, 6:07 AM
Hi ..I used the same code but it is throwing Remote Server Returned an Error:401 Unauthorized. What Should i do?
Pradeep singhPosted Feb 23, 2017, 9:35 AM
Hi sir this is working perfectly for me....Can we use same code for Ios Push notification???.
Akash KumarPosted Feb 23, 2017, 7:29 AM
Above code is working properly, but can share code how to send notification to multiple devices
Priyanka AbrolPosted Feb 22, 2017, 7:05 AM
Hi, can anyone please guide me how registration id is coming here and still not getting it
Nikhil RajputPosted Nov 30, 2016, 12:24 AM
Sir How can I do same for IOS.
IM ServicesPosted Sep 20, 2016, 3:31 AM
Working fine for me
Minhaj AliPosted Jun 22, 2016, 1:50 PM
Notification is coming without message.
Pranav J.DevPosted Mar 29, 2016, 4:55 AM
Very good article
Humayun Kabir MamunPosted Mar 20, 2016, 12:05 AM
Nice...
Kirtan ParmarPosted Mar 18, 2016, 3:47 AM
good one..thanks
Sibeesh VenuPosted Mar 17, 2016, 11:15 AM
Nice Share
Asfend YarPosted Mar 17, 2016, 5:46 AM
good
Vignesh ManiPosted Mar 16, 2016, 5:56 PM
good
Debasis SahaPosted Mar 16, 2016, 1:54 PM
Good One..
kalu singh raoPosted Mar 16, 2016, 12:06 PM
Nice...
Kashif SohailPosted Mar 16, 2016, 11:19 AM
Great Article, Love to see this
Saillesh PawarPosted Mar 16, 2016, 9:47 AM
NIce share
Shaili DashoraPosted Mar 16, 2016, 8:58 AM
Nice Share..helpful
Mohammed IbrahimPosted Mar 16, 2016, 4:29 AM
nice