Using WebRequest and WebResponse classes

Mahesh Chand

7y709.6k20100Article

WebRequestUploading FilesDownloading filesWebResponse classes

20 Comments

Join the conversation! Your thoughts help the community grow.

Raju Paladiya6y ago
Worked awesomely
Rinkesh Dua9y ago
Hye, suppose I uploaded a excel file to http://localhost:portnumber/example.aspx page and it returned with status:ok. Which means it is uploaded, So the question is where it is uploaded or where should I find the uploaded file and same thing for the web server?
Ali Asad10y ago
try { HttpWebRequest request = (HttpWebRequest)WebRequest.Create("address"); ASCIIEncoding encoding = new ASCIIEncoding(); string Postdata = "commandType=123&[email protected]&password=ali"; byte[] data = Encoding.UTF8.GetBytes(Postdata); request.Method = "POST"; request.ContentType = "application/json; charset=utf-8"; request.ContentLength = data.Length; using (var stream = request.GetRequestStream()) { stream.Write(data, 0, data.Length); stream.Close(); } var response = (HttpWebResponse)request.GetResponse(); var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd(); response.Close(); } catch (Exception ex) { Response.Redirect("ErrorPage.aspx"); throw ex; }
- Ali Asad10y ago
  facing the error 500 internal server error..any one helps me out
Sam Hobbs16y agoedited
Anyone using http://www.c-sharpcorner.com/index.asp as a sample to download, use <A href="">http://www.c-sharpcorner.com</A> instead.
Ashutosh Tripathi16y ago
Hello sir .... I am trying to validate URL in a application for win mobile . Following is the code .. try { //MessageBox.Show(_url.ToString()); HttpWebResponse response = (HttpWebResponse)webrequest.GetResponse(); MessageBox.Show("this url is valid"); // jus to display validation url } catch (Exception ex) { MessageBox.Show(ex.ToString()); TextUrl = ""; url.Focus(); } its not working.. throwing an exception.. but same code i tried for a simple windows form application.. there it worked... :(
Kumar Vaibhav16y ago
Hi Mahesh, I am trying to connect a exchange server to retrieve mail using C# which is SSL secure and I am getting "[System.Net.WebException] = {"The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."}"error.Please help me with the solutions
aamir zada17y ago
hi sir i m getting the same page again and again i have send the __eventtarget and __eventargumnet value as describe in javascript:_autopostback(controlname,'Page$2'), along with all other data but it still get the same page. can you please help me or give me a refrence of a book or anyother thing discuss these topic in depth thank you
Brian Markey17y ago
I am writing a small application to connect to a remote server and obtain information in XML. As a starting point I am using the WeatherTracker example in Microsoft's "Build a Program Now!" book for Visual C# 2008. Unfortunately, the example returns the error, "Unable to connect to remote server". When I ctrl-click on the link in the editor, the appropriate XML is obtained from the server (i.e. the URL is valid). So, why does it NOT work when called within the code? Here's a code nippet: string feedUrl = "http://weather.service.msn.com/data.aspx?src=vista&wealocations=wc:USWA0367"; XmlTextReader reader = new XmlTextReader(feedUrl); bool firstForecastDone = false; string skyImagesRelativeUrl = "Images/"; int MaxTemp, MinTemp, CurrentTemp, FeelsLike, Humidity, SkyCode; try { while (reader.Read()) . . . Suggestions would be much appreciated Brian
Former member17y ago
Let me know one thing . If i want to receive some string from another application, what is the code i have to had in my asp .net page ? The protocol i want to use is the HTTP , i dont know what function i must use . Please Help me
ashish pandey17y ago
i am using webrequest class for reading data from another site,there is paging on site with 1,2,3 input button ,i am getting first page result,but i am unable to get the next page result ,i want to find the button control and get it click through programitically. please help me
- Mahesh Chand17y ago
  I am not sure if you can do that using this approach. Since, the control is a server side control, the event has to be fired on the server. I am afraid, you may not be able to do that. Unless the website owner provide some kind of function that can be called from the caller applications.
abhi manav19y ago
Im developing an API which would download a CSV file from a server. I hope i can download it using the HttpWebRequest class. in the create method where i pass the URI, i will pass the link to the server , do i need to specify he filename also in the URI. Please advice me! Thanks in advance.
- Blocked Account17y ago
  Yes, U have to specify file name also.
malini mr19y ago
hello sir, i am doing my project proxy server in c#.net and i am having a module for site and ip blocking.i am not able to make it a success. so, can u pls provide me the code for site/ip blocking thank u
- Mahesh Chand17y ago
  All non article related questions should be posted on the forums.
Raja S19y ago
Hi.. Suppose i have two values like SSN and ID i want to post it at website(URL) and get response is reply message from curresponding website,then what code we write to send and get the response using httpwebrequest/response. Plz guide me.. with regards Raja.S
Rajkumar kumar19y agoedited
Hi.. Suppose i have two value like val="10" and val2="20", i want to post it at xyz.com and get response is sum of these value,then what code we write to send and get the response using httpwebrequest/response. Plz guide me.. with regards Ranjan Gupta New Delhi India (09873507465 )
- Mahesh Chand19y agoedited
  I don't think you can do this using direct request and response. You will have to run a Web Service on the domain and call its method. Method will take two parameters and return the sum. Check Web Services section of this site to learn how to Create a Web Service and client applications.
rashmi20y ago
I m getting Error 405 while uploading file using web client. Can uploading be done throuh web request oobject. How can it be done, Please guide me . Thanks in advance, Rashmi

Upload Data

The WebClient class provides four different ways to uploading data to a resource.

The OpenWrite method sends a data stream to the resource. It's reverse operation of OpenRead method. You pass URI as first parameter of OpenWrite.

OpenWrite(string);

The UploadData method sends a byte array to the resource and returns a byte array containing any response. It's a reverse operation of DownloadData method. It takes two arguments of string and array of bytes respectively.

UploadData(string, byte[]);
client.UploadData("http://www.mindcracker.com/testfile.bmp", data);

The UploadFile method sends a local file to the resource and returns a byte array containing any response. It's a reverse operation of DownloadFile. UploadFile also takes two parameters. First a URI name and second file to be uploaded.

UploadFile(string string);
client.UploadFile("http://www.mindcracker.com/tst.gif", @"c:\mcb.gif");
//Or:
client.UploadFile("http://www.mindcracker.com/test.htm", @"c:\test.htm");

The UploadValues sends a NameValueCollection to the resource and returns a byte array containing any response.

UploadValues(string, NameValueCollection);

Using WebRequest and WebResponse Classes

Although you can use WebClient class to upload and download data but there are more things involved in uploading and downloading data. What if you don't have right to upload to the server you are uploading to? Did you see us passing userid and passwords for the server somewhere? We didn't think so. So if you don't have permission to write to the server, you get this error.

So what we do now? That's where boundary of the WebClient class ends. And that's where the WebRequest and WebResponse classes come in the existence.

The WebRequest Class

The WebRequest is an abstract base class. So you actually don't use it directly. You use it through it derived classes - HttpWebRequest and FileWebRequest.

You use Create method of WebRequest to create an instance of WebRequest. GetResponseStream returns data stream. The following sample example downloads data stream from a web page.

Sample Code

using System;
using System.Net;
using System.IO;
namespace WebRequestSamp
{
/// <summary>
/// Summary description for Class1.
/// </summary>
class Class1
{
static void Main(string[] args)
{
WebRequest request = WebRequest.Create(https://www.c-sharpcorner.com/index.asp);
WebResponse response = request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string str = reader.ReadLine();
while(str != null)
{
Console.WriteLine(str);
str = reader.ReadLine();
}
}
}
}

HttpWebRequest and HttpWebResponse classes works in same way too. Here is one sample example.

Using HttpWebRequest and HttpWebResponse Classes

HttpWebRequest request = (HttpWebRequest)WebRequest.Create (https://www.microsoft.com );
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
String ver = response.ProtocolVersion.ToString();
StreamReader reader = new StreamReader(response.GetResponseStream() );
string str = reader.ReadLine();
while(str != null)
{
Console.WriteLine(str);
str = reader.ReadLine();
}

Well .. that's it for now. My next submission is Web Browser. It should be up on the site soon.

Member	Type	Description
BaseURI	Property	Current base URL address
Headers	Property	Headers in the form of name and value pair associated with the request.
QueryStrings	Property	Queries in the form of name and value pair associated with the request.
ResponseHeaders	Property	Headers in the form of name and value pair associated with the response.
DownloadData	Method	Download data from a URI and returns data as a byte array.
DownloadFile	Method	Download data from a URI and saves as a local file.
OpenRead	Method	Opens and reads a URI in stream form.
OpenWrite	Method	Opens a stream to write data to a URI.
UploadData	Method	Uploads data buffer to a URI.
UploadFile	Method	Uploads a local file to the given URI.
UploadValues	Method	Uploads name and value collection.

Using WebClient Class

Using WebRequest and WebResponse Classes

Using HttpWebRequest and HttpWebResponse Classes