I work in a office which requires all connections to be made through a specific http proxy. I need to write a simple application to query some values from a webserver - it's easy if there were no proxy. How can I make the C# application proxy-aware? How can I make any sort of connection through a proxy?
If you are using WebClient
, it has a Proxy property you can use.
As other have mentioned, there are several ways to automate proxy setting detection/usage
Web.Config:
<system.net>
<defaultProxy enabled="true" useDefaultCredentials="true">
<proxy usesystemdefault="true" bypassonlocal="true" />
</defaultProxy>
</system.net>
Use of the WebProxy class as described in this article.
You can also cofigure the proxy settings directly (config or code) and your app will then use those.
Web.Config:
<system.net>
<defaultProxy>
<proxy
proxyaddress="http://[proxy address]:[proxy port]"
bypassonlocal="false"
/>
</defaultProxy>
</system.net>
Code:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("url");
WebProxy myproxy = new WebProxy("[proxy address]:[proxy port]", false);
request.Proxy = myproxy;
request.Method = "GET";
HttpWebResponse response = (HttpWebResponse) request.GetResponse();
If you want the app to use the system default proxy, add this to your Application.exe.config (where application.exe is the name of your application):
<system.net>
<defaultProxy enabled="true" useDefaultCredentials="true">
<proxy usesystemdefault="true" bypassonlocal="true" />
</defaultProxy>
</system.net>
More details can be found on in the MSDN article on System.Net
This is easily achieved either programmatically, in your code, or declaratively in either the web.config or the app.config.
You can programmatically create a proxy like so:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("[ultimate destination of your request]");
WebProxy myproxy = new WebProxy("[your proxy address]", [your proxy port number]);
myproxy.BypassProxyOnLocal = false;
request.Proxy = myproxy;
request.Method = "GET";
HttpWebResponse response = (HttpWebResponse) request.GetResponse();
You're basically assigning the WebProxy
object to the request
object's proxy
property. This request
will then use the proxy
you define.
To achieve the same thing declaratively, you can do the following:
<system.net>
<defaultProxy>
<proxy
proxyaddress="http://[your proxy address and port number]"
bypassonlocal="false"
/>
</defaultProxy>
</system.net>
within your web.config or app.config. This sets a default proxy that all http requests will use. Depending upon exactly what you need to achieve, you may or may not require some of the additional attributes of the defaultProxy / proxy element, so please refer to the documentation for those.
Automatic proxy detection is a process by which a Web proxy server is identified by the system and used to send requests on behalf of the client. This feature is also known as Web Proxy Auto-Discovery (WPAD). When automatic proxy detection is enabled, the system attempts to locate a proxy configuration script that is responsible for returning the set of proxies that can be used for the request.
This code has worked for me:
WebClient wc = new WebClient();
wc.Proxy.Credentials = CredentialCache.DefaultCredentials;