WEBfactory 2010

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using WFSilverlight.Core;

namespace ClientSDKExample
{
    public partial class MainPage : UserControl, IDisposable
    {
        public MainPage()
        {
            InitializeComponent();
            Loaded += UserControl_Loaded; //register to the Loaded event of the UserControl
        }

        private WFConnector wfConnector;
        private const string SignalName = "Setpoint 2";

        //REGISTER and READ operations start here
        private void UserControl_Loaded(object sender, RoutedEventArgs e) //here is what happens when the UserControl is loaded
        {
            if (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(this)) //the next code will happen only at run time
            {
                wfConnector = new WFConnector(false); //initializing new connector instance
                wfConnector.RegisterSignalChangedHandler("", SignalName, SignalChanged); 
		//registering to the signal changed event handler
            }
        }

        void SignalChanged(string name, object value) //the delegate method from the RegisterSignalChangedHandler event handler
        {
            if (value != null)
            {
                SignalValueLabel.Text = value.ToString(); //write the value to the label if it is not null
            }
        }
        
        //WRITE operations start here
        private void SignalInput_KeyUp(object sender, KeyEventArgs e) 
	 //the Key Up event handler method for the SignalInput text bock
        {
            if (e.Key == Key.Enter) //checking if the Entery key is pressed used
            {
                wfConnector.WriteSignal("", SignalName, SignalInput.Text, WriteSignalHandler); 
		//writing the value to the singla
            }
        }

        private void WriteSignalHandler(Exception error, int[] results) //validating the write operation
        {
            var errorCode = results == null ? 0 : results.FirstOrDefault();

            if (!IsWritingSuccessful(error, results)) //displaying the error code if the writing is not succesful
            {
                string errorMessage = error != null
                                            ? error.Message
                                            : "Write failed with error code: " + errorCode;

                MessageBox.Show(errorMessage); //
            }
        }

        private bool IsWritingSuccessful(Exception error, IEnumerable<int> results) 
	//the method that checks if any error code returned when writing
        {
            var errorCode = results == null ? 0 : results.FirstOrDefault();
            return error == null && errorCode == 0;
        }

        //DISPOSE section starts here
        public void Dispose() //the Dispose method from IDisposable
        {
            DisposeConnector();
        }

        private void DisposeConnector()
        {
            if (wfConnector == null) return; //checking if the connector is null
            wfConnector.UnregisterSignalChangedHandler("", SignalName, SignalChanged); 
		//unregistering from the signal changed event handler

            wfConnector.Dispose(); //disposing the connector
            wfConnector = null; //setting the connector to null so it won't be disposed again
        }
    }
}