Csharp/C Sharp/Network/Web Client

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Access the Internet

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Access the Internet. 
 
using System; 
using System.Net; 
using System.IO; 
 
public class NetDemo {  
  public static void Main() { 
    int ch; 
 
    // First, create a WebRequest to a URI. 
    HttpWebRequest req = (HttpWebRequest) 
           WebRequest.Create("http://www.nfex.ru"); 
 
    // Next, send that request and return the response. 
    HttpWebResponse resp = (HttpWebResponse) 
           req.GetResponse(); 
 
    // From the response, obtain an input stream. 
    Stream istrm = resp.GetResponseStream(); 
 
 
    /* Now, read and display the html present at 
       the specified URI.  So you can see what is 
       being displayed, the data is shown 
       400 characters at a time.  After each 400 
       characters are displayed, you must press 
       ENTER to get the next 400. */ 
   
    for(int i=1; ; i++) { 
      ch =  istrm.ReadByte(); 
      if(ch == -1) break; 
      Console.Write((char) ch); 
      if((i%400)==0) { 
        Console.Write("\nPress a key."); 
        Console.Read(); 
      } 
    } 
 
    // Close the Response. This also closes istrm. 
    resp.Close(); 
  } 
}


Basic WebClient

using System;
using System.Collections.Generic;
using System.ruponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Net;
public class MainClass {
    public static void Main() {
        System.Net.WebClient Client = new WebClient();
        Stream strm = Client.OpenRead("http://www.reuters.ru");
        StreamReader sr = new StreamReader(strm);
        string line;
        while ((line = sr.ReadLine()) != null) {
            Console.WriteLine(line);
        }
        strm.Close();
    }
}


Displays the resource specified

using System;
using System.IO;
using System.Net;
public class TryURL {
  public static void Main(String [] args) {
    WebClient client = new WebClient();
    client.BaseAddress = "http://www.nfex.ru";
    client.DownloadFile("www.nfex.ru", "index.htm");
    StreamReader input =new StreamReader(client.OpenRead("index.htm"));
    Console.WriteLine(input.ReadToEnd());
    Console.WriteLine
      ("Request header count: {0}", client.Headers.Count);
    WebHeaderCollection header = client.ResponseHeaders;
    Console.WriteLine
      ("Response header count: {0}", header.Count);
    for (int i = 0; i < header.Count; i++)
      Console.WriteLine("   {0} : {1}", 
                          header.GetKey(i), header[i]);
    input.Close();
  }
}


Download Data Test

using System;
using System.Net;
using System.Text;
public class DownloadDataTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      byte[] response = wc.DownloadData(argv[0]);
      Console.WriteLine(Encoding.ASCII.GetString(response));
   }
}


Download File Test

using System;
using System.Net;
public class DownloadFileTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      string filename = "webpage.htm";
      wc.DownloadFile(argv[0], filename);
      Console.WriteLine("file downloaded");
   }
}


Examine the headers

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Examine the headers. 
 
using System; 
using System.Net; 
 
public class HeaderDemo {  
  public static void Main() { 
 
    // Create a WebRequest to a URI. 
    HttpWebRequest req = (HttpWebRequest) 
           WebRequest.Create("http://www.osborne.ru"); 
 
    // Send that request and return the response. 
    HttpWebResponse resp = (HttpWebResponse) 
           req.GetResponse(); 
 
    // Obtain a list of the names. 
    string[] names = resp.Headers.AllKeys; 
 
    // Display the header name/value pairs. 
    Console.WriteLine("{0,-20}{1}\n", "Name", "Value"); 
    foreach(string n in names) 
      Console.WriteLine("{0,-20}{1}", n, resp.Headers[n]); 
 
    // Close the Response.  
    resp.Close(); 
  } 
}


Handle network exceptions

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Handle network exceptions. 
 
using System; 
using System.Net; 
using System.IO; 
 
public class NetExcDemo {  
  public static void Main() { 
    int ch; 
 
    try { 
 
      // First, create a WebRequest to a URI. 
      HttpWebRequest req = (HttpWebRequest) 
             WebRequest.Create("http://www.osborne.ru"); 
 
      // Next, send that request and return the response. 
      HttpWebResponse resp = (HttpWebResponse) 
             req.GetResponse(); 
 
      // From the response, obtain an input stream. 
      Stream istrm = resp.GetResponseStream(); 
 
      /* Now, read and display the html present at 
         the specified URI.  So you can see what is 
         being displayed, the data is shown 
         400 characters at a time.  After each 400 
         characters are displayed, you must press 
         ENTER to get the next 400. */ 
   
      for(int i=1; ; i++) { 
        ch =  istrm.ReadByte(); 
        if(ch == -1) break; 
        Console.Write((char) ch); 
        if((i%400)==0) { 
          Console.Write("\nPress a key."); 
          Console.Read(); 
        } 
      } 
 
 
      // Close the Response. This also closes istrm. 
      resp.Close(); 
 
    } catch(WebException exc) { 
      Console.WriteLine("Network Error: " + exc.Message +  
                        "\nStatus code: " + exc.Status); 
    } catch(ProtocolViolationException exc) { 
      Console.WriteLine("Protocol Error: " + exc.Message); 
    } catch(UriFormatException exc) { 
      Console.WriteLine("URI Format Error: " + exc.Message); 
    } catch(NotSupportedException exc) { 
      Console.WriteLine("Unknown Protocol: " + exc.Message); 
    } catch(IOException exc) { 
      Console.WriteLine("I/O Error: " + exc.Message); 
    } 
  } 
}


My Web Client

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 * Version: 1
 */
using System;
using System.Net;
using System.Text;
using System.IO;

namespace Client.Chapter_14___Networking_and_WWW
{
  public class MyWebClient
  {
    [STAThread]
    static void Main(string[] args)
    {
      WebClient MyClient = new WebClient();
      Stream MyStream = MyClient.OpenRead("http://www.nfex.ru.ru");
      StreamReader MyReader = new StreamReader(MyStream);
      Console.WriteLine(MyReader.ReadLine());
      MyStream.Close();
    }
  }
}


NetworkCredential Cache Test

/*
C# Network Programming 
by Richard Blum
Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.Net;
using System.Text;
public class CredCacheTest
{
   public static void Main()
   {
      WebClient wc = new WebClient();
      string website1 = "http://remote1.ispnet.net";
      string website2 = "http://remote2.ispnet.net";
      string website3 = "http://remote3.ispnet.net/login";

      NetworkCredential nc1 = new NetworkCredential("mike", "guitars");
      NetworkCredential nc2 = new NetworkCredential("evonne", "singing", "home");
      NetworkCredential nc3 = new NetworkCredential("alex", "drums");
      CredentialCache cc = new CredentialCache();
      cc.Add(new Uri(website1), "Basic", nc1);
      cc.Add(new Uri(website2), "Basic", nc2);
      cc.Add(new Uri(website3), "Digest", nc3);
      wc.Credentials = cc;
      wc.DownloadFile(website1, "website1.htm");
      wc.DownloadFile(website2, "website2.htm");
      wc.DownloadFile(website3, "website3.htm");
   }
}


NetworkCredential test

using System;
using System.Net;
using System.Text;
public class CredTest
{
   public static void Main()
   {
      WebClient wc = new WebClient();
      NetworkCredential nc = new NetworkCredential("alex", "mypassword");
      wc.Credentials = nc;
      byte[] response = wc.DownloadData("http://www.nfex.ru/index.htm");
      Console.WriteLine(Encoding.ASCII.GetString(response));
   }
}


Reading Web Pages

/*
A Programmer"s Introduction to C# (Second Edition)
by Eric Gunnerson
Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 32 - .NET Frameworks Overview\Reading Web Pages
// copyright 2000 Eric Gunnerson
using System;
using System.Net;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
class QuoteFetch
{
    public QuoteFetch(string symbol)
    {
        this.symbol = symbol;
    }
    
    public string Last
    {
        get
        {
            string url = "http://moneycentral.msn.ru/scripts/webquote.dll?ipage=qd&Symbol=";
            url += symbol;
            
            ExtractQuote(ReadUrl(url));
            return(last);
        }
    }
    string ReadUrl(string url)
    {
        Uri uri = new Uri(url);
        
        //Create the request object
        
        WebRequest req = WebRequest.Create(uri);
        WebResponse resp = req.GetResponse();
        Stream stream = resp.GetResponseStream();
        StreamReader sr = new StreamReader(stream);
        
        string s = sr.ReadToEnd();
        
        return(s);
        
    }
    void ExtractQuote(string s)
    {
        // Line like: "Last</TD><TD ALIGN=RIGHT NOWRAP><B>&nbsp;78 3/16"
        
        Regex lastmatch = new Regex(@"Last\D+(?<last>.+)<\/B>");
        last = lastmatch.Match(s).Groups[1].ToString();
    }
    string    symbol;
    string    last;
}
public class ReadingWebPages
{
    public static void Main(string[] args)
    {
        if (args.Length != 1)
        Console.WriteLine("Quote <symbol>");
        else
        {
            // GlobalProxySelection.Select = new DefaultControlObject("proxy", 80);
            QuoteFetch q = new QuoteFetch(args[0]);
            Console.WriteLine("{0} = {1}", args[0], q.Last);
        }
    }
}


Save web page from HttpWebResponse

using System;
using System.Net;
using System.IO;
public class WebApp {
    public static void Main() {
        String page = "http://www.yoursite.net/index.html";
        HttpWebRequest site = (HttpWebRequest)WebRequest.Create(page);
        HttpWebResponse response =(HttpWebResponse)site.GetResponse();
        Stream dataStream = response.GetResponseStream();
        StreamReader read = new StreamReader(dataStream);
        String data = read.ReadToEnd();
        Console.WriteLine(data);
    }
}


Use LastModified

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Use LastModified. 
 
using System; 
using System.Net; 
 
public class HeaderDemo12 {  
  public static void Main() { 
 
    HttpWebRequest req = (HttpWebRequest) 
           WebRequest.Create("http://www.Microsoft.ru"); 
 
    HttpWebResponse resp = (HttpWebResponse) 
           req.GetResponse(); 
 
    Console.WriteLine("Last modified: " + resp.LastModified); 
 
    resp.Close(); 
  } 
}


Use WebClient to download information into a file

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Use WebClient to download information into a file. 
 
using System; 
using System.Net; 
using System.IO; 
 
public class WebClientDemo {  
  public static void Main() { 
    WebClient user = new WebClient(); 
    string uri = "http://www.nfex.ru"; 
    string fname = "data.txt"; 
     
    try { 
      Console.WriteLine("Downloading data from " + 
                        uri + " to " + fname); 
      user.DownloadFile(uri, fname); 
    } catch (WebException exc) { 
      Console.WriteLine(exc); 
    } catch (UriFormatException exc) { 
      Console.WriteLine(exc); 
    } 
      
    Console.WriteLine("Download complete."); 
  } 
}


Web Client Open Read Test

using System;
using System.IO;
using System.Net;
public class OpenReadTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      string response;
      Stream strm = wc.OpenRead(argv[0]);
      StreamReader sr = new StreamReader(strm);
      while(sr.Peek() > -1)
      {
         response = sr.ReadLine();
         Console.WriteLine(response);
      }
      sr.Close();
   }
}


Web Client Open Write Test

using System;
using System.IO;
using System.Net;
public class OpenWriteTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      string data = "Data up upload to server";
      Stream strm = wc.OpenWrite(argv[0]);
      StreamWriter sw = new StreamWriter(strm);
      sw.WriteLine(data);
      sw.Close();
      strm.Close();
   }
}


Web Client Response Headers Test

using System;
using System.Collections.Specialized;
using System.Net;
public class ResponseHeadersTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      byte[] response = wc.DownloadData(argv[0]);
      WebHeaderCollection whc = wc.ResponseHeaders;
      Console.WriteLine("header count = {0}", whc.Count);
      for (int i = 0; i < whc.Count; i++)
      {
         Console.WriteLine(whc.GetKey(i) + " = " + whc.Get(i));
      }
   }
}


Web Client Upload Data Test 2

using System;
using System.Net;
using System.Text;
public class UploadDataTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      string data = "This is the data to post";
      byte[] dataarray = Encoding.ASCII.GetBytes(data);
      wc.UploadData(argv[0], dataarray);
   }
}


Web Client Upload Values Test

using System;
using System.Collections.Specialized;
using System.Net;
using System.Text;
public class UploadValuesTest
{
   public static void Main(string[] argv)
   {
      WebClient wc = new WebClient();
      string uri = "http://localhost/testform.aspx";
      NameValueCollection nvc = new NameValueCollection();
      nvc.Add("lastname", "Blum");
      nvc.Add("firstname", "Rich");
      byte[] response = wc.UploadValues(uri, nvc);
      Console.WriteLine(Encoding.ASCII.GetString(response));
   }
}


Web Get

/*
C# Network Programming 
by Richard Blum
Publisher: Sybex 
ISBN: 0782141765
*/
using System;
using System.Drawing;
using System.IO;
using System.Net;
using System.Windows.Forms;
public class WebGet : Form
{
   private TextBox uribox;
   private ListBox headers;
   private ListBox cookies;
   private ListBox response;
   public WebGet()
   {
      Text = "WebGet - a web page retriever";
      Size = new Size(500, 450);
      Label label1 = new Label();
      label1.Parent = this;
      label1.Text = "URI:";
      label1.AutoSize = true;
      label1.Location = new Point(10, 23);
      uribox = new TextBox();
      uribox.Parent = this;
      uribox.Size = new Size(200, 2 * Font.Height);
      uribox.Location = new Point(35, 20);
      Label label2 = new Label();
      label2.Parent = this;
      label2.Text = "Headers:";
      label2.AutoSize = true;
      label2.Location = new Point(10, 46);
      headers = new ListBox();
      headers.Parent = this;
      headers.HorizontalScrollbar = true;
      headers.Location = new Point(10, 65);
      headers.Size = new Size(450, 6 * Font.Height);
      Label label3 = new Label();
      label3.Parent = this;
      label3.Text = "Cookies:";
      label3.AutoSize = true;
      label3.Location = new Point(10, 70 + 6 * Font.Height);
      cookies = new ListBox();
      cookies.Parent = this;
      cookies.HorizontalScrollbar = true;
      cookies.Location = new Point(10, 70 + 7 * Font.Height);
      cookies.Size = new Size(450, 6 * Font.Height);
      Label label4 = new Label();
      label4.Parent = this;
      label4.Text = "HTML:";
      label4.AutoSize = true;
      label4.Location = new Point(10, 70 + 13 * Font.Height);
      response = new ListBox();
      response.Parent = this;
      response.HorizontalScrollbar = true;
      response.Location = new Point(10, 70 + 14 * Font.Height);
      response.Size = new Size(450, 12 * Font.Height);

      Button sendit = new Button();
      sendit.Parent = this;
      sendit.Text = "GetIt";
      sendit.Location = new Point(275, 18);
      sendit.Size = new Size(7 * Font.Height, 2 * Font.Height);
      sendit.Click += new EventHandler(ButtongetitOnClick);
   }
   void ButtongetitOnClick(object obj, EventArgs ea)
   {
      headers.Items.Clear();
      cookies.Items.Clear();
      response.Items.Clear();
      HttpWebRequest hwr = (HttpWebRequest)WebRequest.Create(uribox.Text);
      hwr.CookieContainer = new CookieContainer();
      HttpWebResponse hwrsp = (HttpWebResponse)hwr.GetResponse();
      WebHeaderCollection whc = hwrsp.Headers;
      for (int i = 0; i < whc.Count; i++)
      {
         headers.Items.Add(whc.GetKey(i) + " = " + whc.Get(i));
      }
      hwrsp.Cookies = hwr.CookieContainer.GetCookies(hwr.RequestUri);
      foreach(Cookie cky in hwrsp.Cookies)
      {
         cookies.Items.Add(cky.Name + " = " + cky.Value);
      }
      Stream strm = hwrsp.GetResponseStream();
      StreamReader sr = new StreamReader(strm);
      while (sr.Peek() > -1)
      {
         response.Items.Add(sr.ReadLine());
      }
      sr.Close();
      strm.Close();
   }
   public static void Main()
   {
      Application.Run(new WebGet());
   }
}
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