sendsmsactivity.cs

using System;
using System.ComponentModel;
using System.IO;
using System.Net;
using System.Text;
using System.Workflow.ComponentModel;
using System.Workflow.ComponentModel.Design;

namespace MyCompany.Workflow.Messaging.Activities
{
    public class SendSMSActivity : Activity
    {
        public static DependencyProperty NumberProperty = 
            DependencyProperty.Register("Number", typeof(System.String), 
            typeof(SendSMSActivity));
        public static DependencyProperty MessageProperty = 
            DependencyProperty.Register("Message", typeof(System.String), 
            typeof(SendSMSActivity));
        
        [DesignerSerializationVisibilityAttribute
            (DesignerSerializationVisibility.Visible)]
        [BrowsableAttribute(true)]
        [DescriptionAttribute("Destination number of SMS message")]
        [CategoryAttribute("SendSMSActivity Number Property")]
        public string Number
        {
            get
            {
                return ((string)(base.GetValue(SendSMSActivity.NumberProperty)));
            }
            set
            {
                base.SetValue(SendSMSActivity.NumberProperty, value);
            }
        }

        [DesignerSerializationVisibilityAttribute
            (DesignerSerializationVisibility.Visible)]
        [BrowsableAttribute(true)]
        [DescriptionAttribute("Text of SMS message")]
        [CategoryAttribute("SendSMSActivity Message Property")]
        public string Message
        {
            get
            {
                return ((string)(base.GetValue(SendSMSActivity.MessageProperty)));
            }
            set
            {
                base.SetValue(SendSMSActivity.MessageProperty, value);
            }
        }
        
        protected override ActivityExecutionStatus 
            Execute(ActivityExecutionContext context)
        {
            string response;
            
            try
            {
                // Send the SMS Message
                response = SendSMS(Number, Message);
            }
            catch (Exception e)
            {
                response = e.Message;
            }

            // Raise the PageFinished event back to the host
            messageSentEvent(null, new MessageSentEventArgs(response));
                     
            // Notify the runtime that the activity has finished
            return ActivityExecutionStatus.Closed;
        }

        public delegate void MessageSentEventHandler(object sender, 
            MessageSentEventArgs e);

        private event MessageSentEventHandler messageSentEvent;
        public event MessageSentEventHandler MessageSent
        {
            add
            {
                messageSentEvent += value;
            }
            remove
            {
                messageSentEvent -= value;
            }
        }

        public string SendSMS(string number, string text)
        {
            WebClient apiRequest = new WebClient();
            apiRequest.Credentials = CredentialCache.DefaultCredentials;

            //Add a user agent header in case the requested URI contains a query
            apiRequest.Headers.Add("user-agent", 
            "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 2.0.50727;)");

            //Add the SMS details to the apiRequest object
            apiRequest.QueryString.Add("user", "xxxxx");
            apiRequest.QueryString.Add("password", "xxxxx");
            apiRequest.QueryString.Add("api_id", "xxxxx");
            apiRequest.QueryString.Add("to", number);
            apiRequest.QueryString.Add("text", text);

            string baseURI = "http://api.clickatell.com/http/sendmsg";

            Stream responseStream = apiRequest.OpenRead(baseURI);
            StreamReader reader = new StreamReader(responseStream);
            string responseCode = reader.ReadToEnd();

            //Clean up in-memory objects
            reader.Close();
            responseStream.Close();

            return (responseCode);
        }
    }

    public class MessageSentEventArgs
    {
        private string response;
        public string Response
        {
            get { return response; }
        }

        public MessageSentEventArgs(string response)
        {
            this.response = response;
        }
    }
}