How to send SMS /OTP in asp.net using c#

How to send SMS /OTP in asp.net using c#

     Public void SendSms()
        {
            try
            {
                string username = "";
                string password = "";
                string sender = "test";
                string domian = "";
                string Heading1 = "Welcome To your website";
                string Heading2 = string.Concat("Dear ", txtName.Text, ",", "Your Confirmation Is:",                                                       txtcode.Text);
                string end = "Enter this code in the registration form. Thanking You";
                string Msg = string.Concat(Heading1, ",", Heading2, ",", end);
                string pn = txtMobile.Text;
                string result = apicall("http://" + domian + "/WebserviceSMS.aspx?username=" +                           username + "&password=" + password + "&sender=" + sender + "&to=" + pn +                               "&message=" + Msg);       
            }
            catch
            {
            }       
        }

        public string apicall(string url)
        {
            HttpWebRequest httpreq = (HttpWebRequest)WebRequest.Create(url);
            try
            {
                HttpWebResponse httpres = (HttpWebResponse)httpreq.GetResponse();
                StreamReader sr = new StreamReader(httpres.GetResponseStream());
                string results = sr.ReadToEnd();
                sr.Close();
                return results;
            }
            catch
            {
                return "0";
            }
        }

Another Code Snip -

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Net;

using System.Text.RegularExpressions;

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

{

    protected void Page_Load(object sender, EventArgs e)

    {

        textboxRecipient.Width = 400;

        textboxMessage.Width = 450;

        textboxMessage.Rows = 10;

        textboxError.Width = 400;

        textboxError.Rows = 5;

        textboxError.ForeColor = System.Drawing.Color.Red;

        textboxError.Visible = false;

        textboxError.Text = "";

        if (!Page.IsPostBack)

        {

            textboxRecipient.Text = "+441234567";

            textboxMessage.Text = "Test message!";

        }

    }

    protected void buttonSendOnClick(object sender, EventArgs e)

    {

        //are required fields filled in:

        if (textboxRecipient.Text == "")

        {

            textboxError.Text += "Recipient(s) field must not be empty!\n";

            textboxError.Visible = true;

            return;

        }

        //we creating the necessary URL string:

        string ozSURL = "http://127.0.0.1"; //where the SMS Gateway is running

        string ozSPort = "9501"; //port number where the SMS Gateway is listening

        string ozUser = HttpUtility.UrlEncode("admin"); //username for successful login

        string ozPassw = HttpUtility.UrlEncode("abc123"); //user's password

        string ozMessageType = "SMS:TEXT"; //type of message

        string ozRecipients = HttpUtility.UrlEncode(textboxRecipient.Text); //who will get the message

        string ozMessageData = HttpUtility.UrlEncode(textboxMessage.Text); //body of message

        string createdURL = ozSURL + ":" + ozSPort + "/httpapi" +

            "?action=sendMessage" +

            "&username=" + ozUser +

            "&password=" + ozPassw +

            "&messageType=" + ozMessageType +

            "&recipient=" + ozRecipients +

            "&messageData=" + ozMessageData;

        try

        {

            //Create the request and send data to the SMS Gateway Server by HTTP connection

            HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(createdURL);

            //Get response from the SMS Gateway Server and read the answer

            HttpWebResponse myResp = (HttpWebResponse)myReq.GetResponse();

            System.IO.StreamReader respStreamReader = new System.IO.StreamReader(myResp.GetResponseStream());

            string responseString = respStreamReader.ReadToEnd();

            respStreamReader.Close();

            myResp.Close();

            //inform the user

            textboxError.Text = responseString;

            textboxError.Visible = true;

        }

        catch (Exception)

        {

            //if sending request or getting response is not successful the SMS Gateway Server may do not run

            textboxError.Text = "The SMS Gateway Server is not running!";

            textboxError.Visible = true;

        }

    }

}