/Visual Studio 2008/CSSL3LocalMessage/MainPage.xaml.cs

/****************************** Module Header ******************************\

* Module Name:                 MainPage.xaml.cs

* Project:                     CSSL3LocalMessage

* Copyright (c) Microsoft Corporation.

* 

* Local message whiteboard's code behind file.

* 

* This source is subject to the Microsoft Public License.

* See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.

* All other rights reserved.

* 

* History:

* * 9/22/2009 6:34 PM Mog Liang Created

\***************************************************************************/



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 System.Windows.Messaging;

using System.Runtime.Serialization.Json;

using System.IO;

using System.Windows.Ink;



namespace CSSL3LocalMessage

{

    public partial class MainPage : UserControl

    {

        // Preassign two names for LocalMessageReceiver.

        readonly string[] clientnames = { "{36BF6178-53A3-4d0b-8E0D-1E7BD9FBBE62}", "{E62BF131-B5EA-4f1d-B80D-DC083C7F0851}" };

        // Preassign two colors for distinguishing two applications.

        readonly Color[] colors = { Colors.Red, Colors.Green };

        int clientid;



        LocalMessageReceiver _localreceiver;

        LocalMessageSender _localsender;

        DataContractJsonSerializer _jsonserializer;



        public MainPage()

        {

            InitializeComponent();



            _jsonserializer =new DataContractJsonSerializer(inkP.Strokes.GetType());



            // First try.

            // Create receiver with one preset name.

            _localreceiver = new LocalMessageReceiver(clientnames[clientid]);

            _localreceiver.MessageReceived += localreceiver_MessageReceived;

            try

            {

                _localreceiver.Listen();

            }

            catch(Exception e)

            {

                // Second try.

                // Create receiver with another preset name.

                _localreceiver.MessageReceived -= localreceiver_MessageReceived;

                clientid = 1;

                _localreceiver = new LocalMessageReceiver(clientnames[clientid]);

                _localreceiver.MessageReceived += localreceiver_MessageReceived;

                try

                {

                    _localreceiver.Listen();

                }

                catch (Exception e1)

                {

                    // Already has two apllication instance.

                    // Pop messagebox, disable drawing area.

                    MessageBox.Show("Only allow 2 clients.");

                    disablegrid.Visibility = Visibility.Visible;

                    return;

                }

            }



            // Create sender targeting to another application's receiver

            _localsender = new LocalMessageSender(clientnames[(clientid + 1) % 2]);

            _localsender.SendCompleted += localsender_SendCompleted;



            drawbr.Background = new SolidColorBrush(colors[clientid]);

        }



        void localsender_SendCompleted(object sender, SendCompletedEventArgs e)

        {

            // If send message got error, pop messagebox.

            if(e.Error!=null)

                MessageBox.Show("Cannot connect to another client.");

        }



        void localreceiver_MessageReceived(object sender, MessageReceivedEventArgs e)

        {

            // Deserialize json string to stroke object.

            var stream = new MemoryStream();

            var streamwriter = new StreamWriter(stream);

            streamwriter.Write(e.Message);

            streamwriter.Flush();

            var receivedstroke = _jsonserializer.ReadObject(stream) as Stroke;

            stream.Close();



            // Add received stroke to inkPresenter.

            inkP.Strokes.Add(receivedstroke);

        }



        // Attaching MouseLeftButtonDown/MouseMove/MouseLeftButtonUp event

        // to implement drawing functionality.

        Stroke _newStroke;

        private void InkPresenter_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            inkP.CaptureMouse();

            _newStroke = new System.Windows.Ink.Stroke();

            _newStroke.DrawingAttributes.Color = colors[clientid];

            _newStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(inkP));

            inkP.Strokes.Add(_newStroke);

        }



        // Sending message when finishing one stroke.

        private void InkPresenter_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)

        {

            inkP.ReleaseMouseCapture();



            // Serialize stroke object to string.

            var stream = new MemoryStream();

            _jsonserializer.WriteObject(stream, _newStroke);

            stream.Flush();

            stream.Position = 0;

            var obstring = new StreamReader(stream).ReadToEnd();

            stream.Close();



            // Send Serialized stroke.

            if (_localsender != null)

            {

                try

                {

                    _localsender.SendAsync(obstring);

                }

                catch (Exception ex)

                {

                    MessageBox.Show(ex.Message);

                }

            }



            _newStroke = null;

        }



        private void InkPresenter_MouseMove(object sender, MouseEventArgs e)

        {

            if (_newStroke != null)

            {

                _newStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(inkP));

            }

        }

    }

}