Software Programs and Projects

Dowload a YouTube Video Usong C#.Net .How can download YouTube Video using C#.net in windows application


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Net;
using System.Reflection;
using System.IO;
using System.Runtime.InteropServices;

namespace DownloadYouTube
{
public partial class Form1 : Form
{

string current_working_directory = Application.StartupPath; // This is used to determine where to save the video.
string youtube_video_title = "video"; // This gets set near the end of get_download_url()
string strUrl = @"http://www.youtube.com/watch?v=_QUrWjEGj34&feature=fvhl";///* insert video URL here*/


public Form1()
{
InitializeComponent();
}

private void btnDownload_Click(object sender, EventArgs e)
{
string youtube_url = makeYouTubeURLCompliant(strUrl); // This makes the URL compliant with the code.
string download_url = get_download_url(youtube_url); // This extracts the download URL from the YouTube website HTMl source code.
download_video_from_url(download_url); // This actually downloads the video. I haven't tested this as I used someone elses queue download class for my own downloading needs.
}
public string get_download_url(string url)
{
string download_url = null;
string buffer = getYouTubePageContent(url);
string title = string.Empty;

if (buffer.IndexOf("Error:") < 0)
{
int start = 0, end = 0;
string startTag = "/watch_fullscreen?";
string endTag = ";";
start = buffer.IndexOf(startTag, StringComparison.CurrentCultureIgnoreCase);
end = buffer.IndexOf(endTag, start, StringComparison.CurrentCultureIgnoreCase);
string str = buffer.Substring(start + startTag.Length, end - (start + startTag.Length));
string vid = str.Substring(str.IndexOf("video_id"), str.IndexOf("&", str.IndexOf("video_id")) - str.IndexOf("video_id"));
string l = str.Substring(str.IndexOf("&l"), str.IndexOf("&", str.IndexOf("&l") + 1) - str.IndexOf("&l"));
string t = str.Substring(str.IndexOf("&t"), str.IndexOf("&", str.IndexOf("&t") + 1) - str.IndexOf("&t"));
title = str.Substring(str.IndexOf("&title=") + 7);

download_url = "http://youtube.com/get_video?" + vid + l + t;
}

else
{
MessageBox.Show("Error downloading video");
}

youtube_video_title = title;

return download_url;
}


private string makeYouTubeURLCompliant(string url)
{
url = url.Replace("www.youtube.com", "youtube.com");

if (url.IndexOf("http://youtube.com/v/") >= 0)
{
url.Replace("http://youtube.com/v/", "http://youtube.com/watch?v=");
}

if (url.IndexOf("http://youtube.com/watch?v=") < 0)
{
url = "";
}

return (url);
}


// This is a helper method is used by get_download_url()

private string getYouTubePageContent(string url)
{

string buffer;
try
{
string outputBuffer = "where=46038";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.Method = "POST";
req.ContentLength = outputBuffer.Length;
req.ContentType = "application/x-www-form-urlencoded";
StreamWriter swOut = new StreamWriter(req.GetRequestStream());
swOut.Write(outputBuffer);
swOut.Close();
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr = new StreamReader(resp.GetResponseStream());
buffer = sr.ReadToEnd();
sr.Close();
}
catch (Exception exp)
{
buffer = "Error: " + exp.Message.ToString();
}

return (buffer);
}

private void download_video_from_url(string url)
{
WebClient webClient = new WebClient();
webClient.DownloadFileAsync(new Uri(url), @current_working_directory + "\\" + makeTitleFileCompliant(youtube_video_title) + ".flv");
}

// This method makes the YouTube title compliant as a filename

public string makeTitleFileCompliant(string title_uncomp)
{
return title_uncomp.Replace("\\", "").Replace("/", "").Replace("*", "").Replace(":", "").Replace("?", "").Replace("\"", "").Replace("<", "").Replace(">", "").Replace("|", "");

}


}
}