In this tutorial, I am going to show you how to work with a file on a web server to achieve tasks such as registration, activation, etc.

Doing this is actually not as hard as it may sound, but this tutorial will, hopefully, give you a good understanding of how to do this.

Ok, let's get started, first, we want to set up our required namespaces, we will need the following:

using System.Net;
using System.IO;

System.Net will be used by WebRequest & WebResponse.
System.IO will be used by Streams, and Stream Readers

Next, let's set up our variables. These variables will contain information on how to work with the file on the web server:

//The method we will use to send the data, this can be POST or GET.
string requestmethod = "POST";

//Here we will enter the data to send, just like if we where to go to a webpage and enter variables,
// we would type: "www.somesite.com?var1=Hello&var2=Server!"!
string postData = "var1=Hello&var2=Server!";

//The Byte Array that will be used for writing the data to the stream.
byte[] byteArray = Encoding.UTF8.GetBytes(postData);

//The URL of the webpage to send the data to.
string URL = "http://www.google.com/testing/targetpage.php";

//The type of content being send, this is almost always "application/x-www-form-urlencoded".
string contenttype = "application/x-www-form-urlencoded";

//What the server sends back:
string responseFromServer = null;

Ok, now that we have our variables set up, let's create the component that will be handling the data transfers:

We will need a WebRequest item to send the data to the server, and, if we want to get data back, we need a WebResponce item.

Also, we will need a StreamReader and StreamWriter object to send and receive the data.

//Here we will create the WebRequest object, and enter the URL as soon as it is created.
WebRequest request = WebRequest.Create(URL);

//We also need a Stream:
Stream dataStream;

//...And a webResponce,
WebResponse response;


//don't forget the streamreader either!
StreamReader reader;

With that done, the only part left is to send and receive data:

//We will need to set the method used to send the data.
request.Method = requestmethod;
           
//Then the contenttype:
request.ContentType = contenttype;

//content length
request.ContentLength = byteArray.Length;

//ok, now get the request from the webRequest object, and put it into our Stream:
dataStream = request.GetRequestStream();

// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);

// Close the Stream object.
dataStream.Close();

Ok, we just sent that information to the server, now let's get the response:

//Get the responce
response = request.GetResponse();

// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();

//Open the responce stream:
reader = new StreamReader(dataStream);

//read the content into the responcefromserver string
responseFromServer = reader.ReadToEnd();

// Clean up the streams.
reader.Close();
dataStream.Close();
response.Close();

//Now, display the responce!
Console.WriteLine(responseFromServer);