WebRequest System.NotSupportedException

Question

Wrote this in monodevelop:

using System;
using System.Net;
using System.Net.Http;

namespace Hello
{
    public class Hello
    {
        public Hello () {}

        public static WebResponse world(string symbol) {
            WebRequest request = WebRequest.Create("http://yahoo.com");
            WebResponse response = request.GetResponse ();
        }
    }
}

Getting this exception where running:

Unhandled Exception: System.NotSupportedException: http://yahoo.com/ at System.Net.WebRequest.GetCreator (System.String prefix) [0x00000] in :0 at System.Net.WebRequest.Create (System.Uri requestUri) [0x00000] in :0 at System.Net.WebRequest.Create (System.String requestUriString) [0x00000] in :0 at CNBC.Research.LookupUtil.downloadStockHistory (System.String symbol) [0x00000] in :0 at CNBC.MainClass.Main (System.String[] args) [0x00000] in :0 [ERROR] FATAL UNHANDLED EXCEPTION: System.NotSupportedException: http://yahoo.com/ at System.Net.WebRequest.GetCreator (System.String prefix) [0x00000] in :0 at System.Net.WebRequest.Create (System.Uri requestUri) [0x00000] in :0 at System.Net.WebRequest.Create (System.String requestUriString) [0x00000] in :0 at CNBC.Research.Hello.world (System.String symbol) [0x00000] in :0 at CNBC.MainClass.Main (System.String[] args) [0x00000] in :0

I believe it's because it doesn't know what http is but I don't know how to add it.

EDIT:

This may shed light on the problem. It may be because I'm running the wrong version? I also am getting this error:

WARNING: The runtime version supported by this application is unavailable. Using default runtime: v4.0.30319

Should I be running version 3.5 for .NET 3.5?

Answer 1

Please try the below code snippet.

   public static WebResponse world(string symbol) {
        // Create a new 'Uri' object with the specified string.
        Uri myUri =new Uri("http://yahoo.com");
        // Create a new request to the above mentioned URL. 
        WebRequest request= WebRequest.Create(myUri);
        // Assign the response object of 'WebRequest' to a 'WebResponse' variable.
        WebResponse response = request.GetResponse ();

      }

OR

 public static WebResponse world(string symbol) {
        // Create a new 'Uri' object with the specified string.
        Uri myUri =new Uri("http://yahoo.com");
        // Create a new request to the above mentioned URL. 
        WebRequest request= CreateWebRequest(myUri);
        // Assign the response object of 'WebRequest' to a 'WebResponse' variable.
        WebResponse response = request.GetResponse ();

      }


private static HttpWebRequest CreateWebRequest(Uri uri)
{
 var type = Type.GetType("System.Net.HttpRequestCreator, System, Version=4.0.0.0,Culture=neutral, PublicKeyToken=b77a5c561934e089");
    var creator = Activator.CreateInstance(type,nonPublic:true) as IWebRequestCreate;
    return creator.Create(uri) as HttpWebRequest;
}

Answer 2

I've faced this situation once I tried bundling my application with mono runtime to be used on machines that have no runtime installed out of the box.

the solution was to add App.config file to my project with the following contents (copied sections from machine.config file of my installed mono version)

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="system.net" type="System.Net.Configuration.NetSectionG

    roup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <section name="authenticationModules" type="System.Net.Configuration.AuthenticationModulesSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <section name="connectionManagement" type="System.Net.Configuration.ConnectionManagementSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <section name="defaultProxy" type="System.Net.Configuration.DefaultProxySection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <sectionGroup name="mailSettings" type="System.Net.Configuration.MailSettingsSectionGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                <section name="smtp" type="System.Net.Configuration.SmtpSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            </sectionGroup>
            <section name="requestCaching" type="System.Net.Configuration.RequestCachingSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <section name="settings" type="System.Net.Configuration.SettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <section name="webRequestModules" type="System.Net.Configuration.WebRequestModulesSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        </sectionGroup>
      </configSections>

      <system.net>
        <authenticationModules>
            <add type="System.Net.BasicClient, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <add type="System.Net.DigestClient, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <add type="System.Net.NtlmClient, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        </authenticationModules>
        <webRequestModules>
            <add prefix="http" type="System.Net.HttpRequestCreator, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <add prefix="https" type="System.Net.HttpRequestCreator, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <add prefix="file" type="System.Net.FileWebRequestCreator, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <add prefix="ftp" type="System.Net.FtpRequestCreator, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        </webRequestModules>
        <settings>
          <ipv6 enabled="false"/>
          <servicePointManager checkCertificateName="false" checkCertificateRevocationList="false" />
        </settings>
      </system.net>


    </configuration>

Hope this will give you a clue!