how to make web service realtime by signalr

Question

User-1634604574 posted

i have this method inside web service file i want to make it real time with sql by using signalR but is not working real time

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Web.Script.Services;
using System.Web.Services;
using service.Hubs;

using System.Configuration;
using FireSharp.Config;  //contain configuration to connect to c#
using FireSharp.Interfaces;//contain methods 
using FireSharp.Response;//response to the firebase
using Microsoft.AspNet.SignalR;

//using System.Web.Script.Services.ScriptService;


namespace service
{
    /// <summary>
    /// Summary description for WebService1
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]


   [WebMethod]
       // [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
        public  void gettingbranch()
        {

            List<Data> b_list = new List<Data>();
            using (var connection = new SqlConnection(connectionstring))
            {

                connection.Open();

                using (SqlCommand command = new SqlCommand("detail_notification", connection))

                {
                    command.CommandType = CommandType.StoredProcedure;

                    command.Notification = null;

                    SqlDependency.Start(connectionstring);
                    dependency = new SqlDependency(command);
                    dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);

                    if (connection.State == ConnectionState.Closed)
                        connection.Open();

                    var reader = command.ExecuteReader();
                    if (reader.HasRows)
                    {
                        while (reader.Read())
                        {
                            Data d = new Data();
                            d.branch = reader["branch"].ToString();
                            b_list.Add(d);
                        }
                    }

                }

                HttpContext.Current.Response.ContentType = "application/json";
                HttpContext.Current.Response.Write(JsonConvert.SerializeObject(b_list));
                HttpContext.Current.Response.End();

            }
            
}

Answer 1

User61956409 posted

Hi [e-mail],

[e-mail]

i want to make it real time with sql by using signalR but is not working real time

Please share the code of your SignalR client and event handler dependency_OnChange, so that we can troubleshoot the issue better.

Besides, if the new data/message could not been pushed to all connected clients, please debug and check if the dependency_OnChange could be triggered.

With Regards,

Fei Han

Answer 2

User-1634604574 posted

i don't have client i just have that web service file i want to make that method as a realtime after clicking on invoke button show me any change from sql db

here is my hub class

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;
namespace service.Hubs
{
    public class MyHub : Hub
    {


        private static string conString = @"Data Source=**;Initial Catalog=**;User ID=admin;Password=**;MultipleActiveResultSets=true;";
        //private static string conString = ConfigurationManager.ConnectionStrings["con"].ToString();



        private static IHubContext hubContext =
   GlobalHost.ConnectionManager.GetHubContext<MyHub>();

        public static void GetStatus(string message)
        {
            hubContext.Clients.All.acknowledgeMessage(message);
        }

        public void Hello() { Clients.All.hello(); }
        public static void Show()
        {
            IHubContext context = GlobalHost.ConnectionManager.GetHubContext<MyHub>();
            context.Clients.All.displayCustomer();
        }
    }
}

my startup.cs

using Microsoft.Owin;
using Owin;

[assembly: OwinStartup(typeof(AspNetWebApiSignalRDemo.WebApi.Startup))]

namespace AspNetWebApiSignalRDemo.WebApi
{
    public partial class Startup
    {
        public void Configuration(IAppBuilder app)
        {
         
          //  app.MapSignalR();
            app.MapSignalR("/signalr", new Microsoft.AspNet.SignalR.HubConfiguration());

        }
    }
}

Answer 3

User-1634604574 posted

and here is method show in side web service file

private static void dependency_OnChange(object sender, SqlNotificationEventArgs e)
        {

            MyHub.Show();

        }

Answer 4

User-1780421697 posted

If you want to get real time updates from database and display them on your web page as soon as you get them, then you have to use async streams that will allow you to get the records from database and display them on screen, In case of ASP.Net SignalR works fine you can get records by async stream and display on web page using SignalR.

Answer 5

User-1780421697 posted

//Console example
 
class Program
{
        static async Task Main(string[] args)
        {
            await SumCalculation();
            Console.ReadKey();
        }


        private static async Task SumCalculation()
        {
             await foreach (var x in Calc.Sum(10))
            {
                Console.WriteLine("Sum is " + x);
            }
        }


}

    public class Calc
    {
        public static async IAsyncEnumerable<int> Sum(int limit)
        {
            int sum = 0;

            for (var i = 0; i <= limit; i++)
            {
                sum += i;
                await Task.Delay(TimeSpan.FromSeconds(0.5));
                yield return sum;
            }

        }
    }

Answer 6

User-1634604574 posted

how about file web service?

Answer 7

User-1780421697 posted

It does not matter what you are getting in response, what matter is Async Streams that give chunk of data, you just need to call the service and get response from service as soon as you fill the list you get data stream

Answer 8

User-1634604574 posted

but why you didn't signalr?

Answer 9

User475983607 posted

You misunderstand how the technology works.  The service is instantiated when there is an HTTP request.  The service is torn down when the service returns the response.

You need to rethink the approach.  I recommend using SignalR as outlined in the official documentation.

Answer 10

User-1780421697 posted

You can do it with SignalR but in that case you need to get chunk of data by service , i think your page size should be at least 5-10 records then you get record page by page, for example you get first 10 records from service and append them in your grid/datatable then get next 10 records and append them and so on ...