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Thread: Detecting Internet Connections from Your C# Code.

  1. #1

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    Exclamation Detecting Internet Connections from Your C# Code.

    Hi,Knowing whether or not Pc Running and it is connected to internet or not . this article will demostrate the simple and
    easy 3 way to connect with internet .today i simple demostrate one method .let us start .and please don't forget to import the following Namespace.
    Using System.net.Socket;
    Code:
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Net.Sockets;
    
    namespace PrjCheckInternetCon
    {
        public partial class Form1 : Form
        {
            public Form1() {
                InitializeComponent();
            }
    
            private void btCheckInternetCon_Click(object sender, EventArgs e)   {
    
                if (checkInternetCon()){
                    MessageBox.Show("You are Connected to Internet");
                    
                }
                
            }
    
            public bool checkInternetCon() {
                try {
                    TcpClient Tcp = new TcpClient("WWW.GMAIL.COM", 80);
                    Tcp.Close();                
                    return true;
                }
                catch  {
                    return false;
                    
                }
            }
        }
    }

  2. #2

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    Re: Detecting Internet Connections from Your C# Code.

    Hi,Friend today i have been posting my 2nd way to check internet connection . please don't forget to import
    System.Net .i have been using here ipHostEntry object of System.net .
    Code:
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Net;
    
    namespace ConnectInternet
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
    
            public bool Connected(string URL) {
                try {
                    IPHostEntry hostentry = Dns.GetHostEntry(URL);
                    return true;
    
    
                }
                catch{
                    MessageBox.Show("Sorry,Internet is not connected", "Internet N/A", MessageBoxButtons.OK);
                    return false;
                }
            }
    
            private void btcheckInternet_Click(object sender, EventArgs e){
                if (Connected("WWW.GMAIL.COM")) {
                    MessageBox.Show("Internet is  connected", "Internet Available", MessageBoxButtons.OK);
    
                }
    
            }
    
    
    
        }
    }
    Last edited by firoz.raj; Oct 15th, 2013 at 02:02 PM.

  3. #3

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    Re: Detecting Internet Connections from Your C# Code.

    Hi Friends, last but not a least please don't forget to write DLLImport["Wininet.dll"] attribute .following example is simplified way to check internet connectivity .
    Code:
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Runtime.InteropServices;
    
    
    
    namespace CONNECTIVITY{
    
        public partial class frmInternetcheck2 : Form
        {
            [DllImport("wininet.dll")]
            private extern static bool internetgetConnectionState(out int description, int reservedValue);
            public frmInternetcheck2()
            {
                InitializeComponent();
            }
    
            private void btcheckinternet_Click(object sender, EventArgs e)  {
                if (checkInternetConnection()) {
                    MessageBox.Show("Connected");
                    
                }
    
                else {
                    MessageBox.Show("Not Connected");                
                    
                }
    
            }
    
            public static bool checkInternetConnection() {
                try {
                    int condesc;
                   return  internetgetConnectionState(out condesc, 0); 
    
                }
                catch {
                    return false;
                }
            }
        }
    }

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