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Chapter 6 Part 6:

Introduction to System.Net

 

 

What do we have in this chapter 6 Part 6?

  1. C# HTTP Protocol Program Example

  2. VB .NET HTTP Protocol Program Example

 

C# HTTP Protocol Program Example

 

Create a new console application project. You can use the project and solution names as shown in the following Figure.

 

C# HTTP Protocol Program Example - a new console application project creation

 

Add the following code.

 

using System;

using System.IO;

using System.Net;

using System.Text;

 

namespace HttpChap6CS

{

    /// <summary>

    /// Demonstrates the use of HttpWebRequest by

    /// downloading the contents of a URL and displaying

    /// them on the console.

    /// </summary>

    class Program

    {

        [STAThread]

        static void Main(string[] args)

        {

            try

            {

                // Create the request object, change the URI if you want

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.cuil.com/");

 

                // Optionally, you can set HTTP-specific elements on the request, such as the User-Agent header

                request.UserAgent = "Test Client version 1.0";

 

                // Issue the request

                HttpWebResponse response = (HttpWebResponse)request.GetResponse();

                Console.WriteLine("GetResponse() is OK...");

 

                // Read the content

                StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.ASCII);

                string content = reader.ReadToEnd();

                Console.WriteLine("ReadToEnd() is OK...");

 

                // Display the content to the console

                Console.WriteLine(content);

                Console.WriteLine("WriteLine() is OK...");

 

            Dim request As HttpWebRequest = WebRequest.Create("http://www.cuil.com/info/")

 

            ' Optionally, you can set HTTP-specific elements on the request, such as the User-Agent header

            request.UserAgent = "Test Client version 1.0"

 

            ' Issue the request

            Dim response As HttpWebResponse = request.GetResponse()

            Console.WriteLine("GetResponse() is OK...")

 

            ' Read the content

            Dim reader As New StreamReader(response.GetResponseStream(), Encoding.ASCII)

            Dim content As String = reader.ReadToEnd()

            Console.WriteLine("ReadToEnd() is OK...")

 

            ' Display the content to the console

            Console.WriteLine(content)

            Console.WriteLine("WriteLine() is OK...")

 

            ' Close the response

            response.Close()

            Console.WriteLine("Close() is OK...")

 

        Catch wex As WebException

            Console.WriteLine(wex.ToString())

            ' Check the status to see if there might be a response object

            If wex.Status = WebExceptionStatus.ProtocolError Then

                Dim response As HttpWebResponse = wex.Response

                Console.WriteLine()

                Console.WriteLine("The protocol error returned was '" & response.StatusCode.ToString & "'.")

                response.Close()

            End If

        End Try

    End Sub

End Module

 

 

 

 

Build and run the project (Start Without Debugging). The following is a sample output.

 

VB .NET HTTP Protocol Program Example - a sample output

 


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