SignalR (Windows Form) : ตัวอย่างการรับส่งข้อมูลแบบ Real Time และการจัดเก็บลงใน Database

CREATE TABLE [dbo].[mytable](
	[id] [int] IDENTITY(1,1) NOT NULL,
	[name] [varchar](150) NULL,
	[email] [varchar](150) NULL,
 CONSTRAINT [PK_mytable] PRIMARY KEY CLUSTERED 
(
	[id] ASC
));

using Microsoft.AspNet.SignalR;
using Microsoft.Owin.Cors;
using Microsoft.Owin.Hosting;
using System.Collections.Generic;
using Owin;
using System;
using System.Reflection;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Newtonsoft.Json;

namespace SignalRServer
{

    public class MyHub : Hub
    {
        public class mytable
        {
            public string name { get; set; }
            public string email { get; set; }
        }

        public void SaveData(string name, string email)
        {
            string json = string.Empty;

            SqlConnection objConn;
            SqlCommand objCmd;
            String strConnString, strSQL;
            SqlDataReader dtReader;

            strConnString = @"Server=localhost;UID=sa;PASSWORD=;database=mydatabase;Max Pool Size=400;Connect Timeout=600;";
            objConn = new System.Data.SqlClient.SqlConnection(strConnString);
            objConn.Open();

            // Insert New Data
            if (name != string.Empty && email != string.Empty)
            {
                strSQL = "INSERT INTO mytable (name, email) " +
                "VALUES ('" + name + "','" + email + "')";
                objCmd = new SqlCommand();
                objCmd.Connection = objConn;
                objCmd.CommandType = CommandType.Text;
                objCmd.CommandText = strSQL;
                objCmd.ExecuteNonQuery();
            }

            // Get Data
            strSQL = "SELECT * FROM mytable order by id asc";
            objCmd = new SqlCommand(strSQL, objConn);
            dtReader = objCmd.ExecuteReader();

            var ls = new List<mytable>();
            if(dtReader.HasRows)
            {
                while (dtReader.Read())
                {
                    ls.Add(new mytable { name = dtReader["name"].ToString(), email = dtReader["email"].ToString() });
                }
            }
            json = JsonConvert.SerializeObject(ls);

            dtReader.Close();
            objCmd = null;
            objConn.Close();
            objConn = null;


            Clients.All.displayData(json);
        }
        public override Task OnConnected()
        {
            Program.MainForm.WriteToConsole("Client connected: " + Context.ConnectionId);
            return base.OnConnected();
        }
        public override Task OnDisconnected(bool stopCalled)
        {
            Program.MainForm.WriteToConsole("Client disconnected: " + Context.ConnectionId);
            return base.OnDisconnected(true);
        }
    }

}

using Microsoft.AspNet.SignalR.Client;
using System;
using System.Net.Http;
using System.Collections.Generic;
using System.Windows.Forms;
using Newtonsoft.Json;

namespace SignalRClient
{
    public partial class ClientStart : Form
    {
        public class mytable
        {
            public string name { get; set; }
            public string email { get; set; }
        }

        private IHubProxy HubProxy { get; set; }
        const string ServerURI = "http://localhost:8080/signalr";
        private HubConnection Connection { get; set; }

        public ClientStart()
        {
            InitializeComponent();
        }

        private void ButtonConnect_Click(object sender, EventArgs e)
        {
            StatusText.Visible = true;
            StatusText.Text = "Connecting to server...";
            ConnectAsync();
        }
        private void ButtonSave_Click(object sender, EventArgs e)
        {
            HubProxy.Invoke("SaveData", TextBoxName.Text, TextBoxEmail.Text);
            TextBoxName.Text = String.Empty;
            TextBoxEmail.Text = String.Empty;
        }

        private async void ConnectAsync()
        {
            Connection = new HubConnection(ServerURI);
            Connection.Closed += Connection_Closed;
            HubProxy = Connection.CreateHubProxy("MyHub");
            HubProxy.On<string>("DisplayData", (json) =>
                this.Invoke((Action)(() =>
                    SetDataGridView(json)
                ))
            );
            try
            {
                await Connection.Start();
            }
            catch (HttpRequestException)
            {
                StatusText.Text = "Unable to connect to server: Start server before connecting clients.";
                return;
            }

            //Activate UI
            ButtonSave.Enabled = true;
            TextBoxName.Enabled = true;
            TextBoxEmail.Enabled = true;
            ButtonConnect.Enabled = false;
            RichTextBoxConsole.AppendText("Connected to server at " + ServerURI + Environment.NewLine);
            FirstLoad();
        }

        public void FirstLoad()
        {
            HubProxy.Invoke("SaveData", string.Empty, string.Empty);
        }

        public void SetDataGridView(string json) {

            var ls = JsonConvert.DeserializeObject<List<mytable>>(json);
            this.myDataGridView.DataSource = ls;
        }

        private void Connection_Closed()
        {
            //Deactivate chat UI; show login UI. 
            this.Invoke((Action)(() => ButtonSave.Enabled = false));
            this.Invoke((Action)(() => StatusText.Text = "You have been disconnected."));
        }

    }
}