Create HTTP post request and receive response using C# console application

Question

I need to post data to a URL (https://somesite.com) to download file in responseStrem based on the parameters I posted. How can I do that using a C# console application?

Parameters: filename, userid, password, type

Answer 1

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Net; using System.IO;  namespace WebserverInteractionClassLibrary {     public class RequestManager     {         public string LastResponse { protected set; get; }          CookieContainer cookies = new CookieContainer();          internal string GetCookieValue(Uri SiteUri,string name)         {             Cookie cookie = cookies.GetCookies(SiteUri)[name];             return (cookie == null) ? null : cookie.Value;         }          public string GetResponseContent(HttpWebResponse response)         {             if (response == null)             {                 throw new ArgumentNullException("response");             }             Stream dataStream = null;             StreamReader reader = null;             string responseFromServer = null;              try             {                 // Get the stream containing content returned by the server.                 dataStream = response.GetResponseStream();                 // Open the stream using a StreamReader for easy access.                 reader = new StreamReader(dataStream);                 // Read the content.                 responseFromServer = reader.ReadToEnd();                 // Cleanup the streams and the response.             }             catch (Exception ex)             {                 Console.WriteLine(ex.Message);             }             finally             {                                 if (reader != null)                 {                     reader.Close();                 }                 if (dataStream != null)                 {                     dataStream.Close();                 }                 response.Close();             }             LastResponse = responseFromServer;             return responseFromServer;         }          public HttpWebResponse SendPOSTRequest(string uri, string content, string login, string password, bool allowAutoRedirect)         {             HttpWebRequest request = GeneratePOSTRequest(uri, content, login, password, allowAutoRedirect);             return GetResponse(request);         }          public HttpWebResponse SendGETRequest(string uri, string login, string password, bool allowAutoRedirect)         {             HttpWebRequest request = GenerateGETRequest(uri, login, password, allowAutoRedirect);             return GetResponse(request);         }          public HttpWebResponse SendRequest(string uri, string content, string method, string login, string password, bool allowAutoRedirect)         {             HttpWebRequest request = GenerateRequest(uri, content, method, login, password, allowAutoRedirect);             return GetResponse(request);         }          public HttpWebRequest GenerateGETRequest(string uri, string login, string password, bool allowAutoRedirect)         {             return GenerateRequest(uri, null, "GET", null, null, allowAutoRedirect);         }          public HttpWebRequest GeneratePOSTRequest(string uri, string content, string login, string password, bool allowAutoRedirect)         {             return GenerateRequest(uri, content, "POST", null, null, allowAutoRedirect);         }          internal HttpWebRequest GenerateRequest(string uri, string content, string method, string login, string password, bool allowAutoRedirect)         {             if (uri == null)             {                 throw new ArgumentNullException("uri");             }             // Create a request using a URL that can receive a post.              HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);             // Set the Method property of the request to POST.             request.Method = method;             // Set cookie container to maintain cookies             request.CookieContainer = cookies;             request.AllowAutoRedirect = allowAutoRedirect;             // If login is empty use defaul credentials             if (string.IsNullOrEmpty(login))             {                 request.Credentials = CredentialCache.DefaultNetworkCredentials;             }             else             {                 request.Credentials = new NetworkCredential(login, password);             }             if (method == "POST")             {                 // Convert POST data to a byte array.                 byte[] byteArray = Encoding.UTF8.GetBytes(content);                 // Set the ContentType property of the WebRequest.                 request.ContentType = "application/x-www-form-urlencoded";                 // Set the ContentLength property of the WebRequest.                 request.ContentLength = byteArray.Length;                 // Get the request stream.                 Stream dataStream = request.GetRequestStream();                 // Write the data to the request stream.                 dataStream.Write(byteArray, 0, byteArray.Length);                 // Close the Stream object.                 dataStream.Close();             }             return request;         }          internal HttpWebResponse GetResponse(HttpWebRequest request)         {             if (request == null)             {                 throw new ArgumentNullException("request");             }             HttpWebResponse response = null;             try             {                 response = (HttpWebResponse)request.GetResponse();                                 cookies.Add(response.Cookies);                                 // Print the properties of each cookie.                 Console.WriteLine("\nCookies: ");                 foreach (Cookie cook in cookies.GetCookies(request.RequestUri))                 {                     Console.WriteLine("Domain: {0}, String: {1}", cook.Domain, cook.ToString());                 }             }             catch (WebException ex)             {                 Console.WriteLine("Web exception occurred. Status code: {0}", ex.Status);             }             catch (Exception ex)             {                 Console.WriteLine(ex.Message);             }             return response;         }      } } 

Answer 2

Take a look at the System.Net.WebClient class, it can be used to issue requests and handle their responses, as well as to download files:

http://www.hanselman.com/blog/HTTPPOSTsAndHTTPGETsWithWebClientAndCAndFakingAPostBack.aspx

http://msdn.microsoft.com/en-us/library/system.net.webclient(VS.90).aspx