Wireless Push

• Download source code - 56.5 KB

Introduction  

This article was published on my website on 2^nd September, 2008. I put it here in order to let more people read it. I welcome any suggestions and questions. 

Problem: I listen to music while I am driving. I plug my MP3 player into my car, and enjoy whatever it has in there. The memory is not big enough, so that I have to reload some new music once in a while. It bothers me because I have to remind myself to take the player into my room, and take it back to my car. I need a new solution to make my life easier. 

Solution: Using wireless - I have a PDA with built-in GPS, so I keep it in my car all the time in case I cannot find my way home. It runs Windows Mobile 5.0, and has .NET 2.0 Framework, and a wireless card as well. I wrote two pieces of applications in C#. One is the Server running on my PDA, the other is the Client running on my desktop in my room.  

Using the Code

How It Works

I drive home, and park my car outside the house. I connect to my wireless router (no internet needed) using PDA's wireless card. I will get an IP address (normally, I set it static as default). I start my Server program on the PDA, ready to listen to the connection. I turn off other applications and darken the screen to save power. I lock my car, and go into my room. Then I run the Client program on my desktop, specify the server IP (usually it sets as default). I choose a folder where I want my music to be pushed. I press "Start to send" to begin the job.

Screenshots

Source Code

// author: sunny sun
// website: www.sunnyspeed.com
// date: September, 2008
// Client on PC with GUI

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.IO;

namespace Client_GUI
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Client_GUI.sendingPath = "";
            Client_GUI.receiverIP = textBox1.Text;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (Client_GUI.sendingPath.Length > 0)
            {
                Client_GUI.receiverIP = textBox1.Text;
                button1.Enabled = false;
                button2.Enabled = false;
                textBox1.Enabled = false;
                backgroundWorker1.RunWorkerAsync();
            }
            else
                MessageBox.Show("Please select file sending path");
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            label5.Text = Client_GUI.sendingPath;
            label3.Text = Client_GUI.curMsg;
        }

        Client_GUI obj = new Client_GUI();
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            obj.StartSend();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog fd = new FolderBrowserDialog();
            if (fd.ShowDialog() == DialogResult.OK)
            {
                Client_GUI.sendingPath = fd.SelectedPath;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }
    }

    //FILE TRANSFER USING C#.NET SOCKET - SERVER
    class Client_GUI
    {
        TcpClient tcpClient;
        static NetworkStream nStream;
        static StreamWriter writeImageData;

        static string Base64ImageData;
        static string BlockData;
        static int RemainingStringLength = 0;
        static string fileName; // include the path and file name

        public Client_GUI()
        {
            
        }

        public static string sendingPath;
        public static string curMsg = "IDLE...";
        public static string receiverIP;

        public void StartSend()
        {
            // that's the IP you want to connect to, and any number for the port
            tcpClient = new TcpClient(receiverIP, 5657); 
            nStream = tcpClient.GetStream();
            writeImageData = new StreamWriter(nStream);

            try
            {
                string[] filePaths = Directory.GetFiles(sendingPath);
                byte[] ImageData;

                foreach (string i in filePaths) // get all files in a directory
                {
                    fileName = i;
                    string fn = i.Substring(i.LastIndexOf('\\') + 1);
                    // send the file name over first
                    // just the file name, not the file path
		  writeImageData.WriteLine(fn); 

                    writeImageData.Flush();
                    //curMsg = "Sent file name: " + fn; //too fast to be seen

                    //start sending the file content
                    FileStream fs = File.OpenRead(fileName);
                    ImageData = new byte[fs.Length];
                    fs.Read(ImageData, 0, ImageData.Length);

                    Base64ImageData = Convert.ToBase64String(ImageData);

                    int bufferSize = 100;   // up to you
                    int ttl = Base64ImageData.Length / bufferSize;
                    RemainingStringLength = Base64ImageData.Length - ttl * bufferSize;

                    //curMsg = "Transferring " + fn;

                    for (int offset = 0; offset <= ttl; offset++)
                    {
                        if (offset < ttl)
                        {
                            BlockData = Base64ImageData.Substring
					(offset * bufferSize, bufferSize);
                        }
                        // deal with the last chunk of data, if there is any left
		      else if (offset == ttl && RemainingStringLength != 0)   
                        {
                            BlockData = Base64ImageData.Substring
				(offset * bufferSize, RemainingStringLength);
                        }
                        else
                        {
                            break;
                        }
                        writeImageData.WriteLine(BlockData);
                        writeImageData.Flush();
                        curMsg = "Transferring \"" + fn + "\"    " + 
				(offset * 100 / ttl) + " %";
                    }

                    fs.Close();

                    // send a signal to notice the server one file is completed
                    writeImageData.WriteLine("DONE");
                    writeImageData.Flush();

                    //curMsg = "Transfer Complete: " + fn;
                }

                writeImageData.Close();
                nStream.Close();
                tcpClient.Close();
            }
            catch (Exception er)
            {
                curMsg = "Unable to connect to server";
                curMsg = er.Message;
            }

            curMsg = "All done!";
        }
    }
}

// author: sunny sun
// website: www.sunnyspeed.com
// date: September, 2008
// Server running on the PDA

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using System.Net;
using System.Net.Sockets;
using System.IO;

// this is the server running on my PDA
// listen to the client to connect, and receive the incoming file
namespace Server_pda
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void menuItem1_Click(object sender, EventArgs e)
        {
            Close();    // click "exit" to exit this program
        }

        private void button1_Click(object sender, EventArgs e)
        {
            button1.Enabled = false;

            //string path = ".\\Storage Card\\FromPC\\";  
            // up to you, save into the memory card is way too slow
            //I saved the incoming files in a folder on my PDA
	   string path = ".\\FromPC\\";   

            bool haha = true;

            IPAddress ipAddress = IPAddress.Any;
            TcpListener tcpListener = new TcpListener(ipAddress, 5657);
            tcpListener.Start();
            //label2.Text = "Server started.";

            while (haha)
            {
                TcpClient tcpClient = tcpListener.AcceptTcpClient();
                //label2.Text = "Client connected.";

                NetworkStream nStream = tcpClient.GetStream();
                StreamReader readImageData = new StreamReader(nStream);

                //label2.Text = "Start to receive the file.";

                //receive the first file name first
                string fileName = readImageData.ReadLine();
                // create the first file
	       FileStream fs = new FileStream(path + fileName, FileMode.Create);

                string data;    //received string data
                int counter = 0;    //number of files
                bool moreFile = false;
                byte[] byte_image;  //data to binary file

                while ((data = readImageData.ReadLine()) != null)
                {
                    if (moreFile)
                    {
                        fileName = data;
                        // create the file
                        fs = new FileStream(path + fileName, FileMode.Create); 
		      moreFile = false;
                    }
                    else if (data.Equals("DONE"))    // one file is finished
                    {
                        moreFile = true;
                        counter++;  // count files

                        //clean
                        fs.Flush();
                        fs.Close();
                        nStream.Flush();
                        GC.Collect();
                        GC.WaitForPendingFinalizers();
                    }
                    else
                    {
                        byte_image = Convert.FromBase64String(data.ToString());
                        fs.Write(byte_image, 0, byte_image.Length);
                    }
                }

                readImageData.Close();
                nStream.Close();
                tcpClient.Close();

                if (counter > 1)
                {
                    label2.Text = counter + " files are saved.";
                }
                else
                {
                    label2.Text = counter + " file is saved.";
                }
            }
        }
    }
}	 

Points of Interest

1. PDA can be turned off automatically after a certain time. However, I let it run all the time, so that I can push music whenever I want to. The standby mode doesn't consume too much power. The PDA can be charged on the go, or charged using solar power.
2. I can download the PC Client here, so that I can get it anywhere (work, friends' place, etc.), and push new music to my device. NICE!  

History

• 24^th September, 2008: Initial post