How can I set an HTTP Proxy (WebProxy) on a WCF client-side Service proxy?

You could also try this :

Programmatically get whatever binding you are using,and then set the proxy on it directly e.g.

var binding = new WSDualHttpBinding("WSDualHttpBinding_IMainService");
binding.ProxyAddress = new Uri("http://192.168.5.1:3128");

where "WSDualHttpBinding_IMainService" is the name of your binding from your config file. Also you have to set UseDefaultWebProxy=false; otherwise your proxy will be ignored.

The proxy settings are part of the binding configuration. For example, look at the ProxyAddress property of the BasicHTTPBinding and WSHttpBinding classes/configuration elements.

Looks like you're leaving your endpoint configuration in the app.config file, in which case you should be able to set the address there.

It makes sense that there is no Proxy property on the WCF proxy, because not all WCF proxies use HTTP for communication. After further review, I found that it is possible to set the proxy in WCF programmatically, if the WCF proxy uses an HTTP binding. I am documenting it here in case someone else needs it. To set the HTTP Proxy in code for a WCF client, do this:

// instantiate a proxy for the service
var svc= new ServiceClient();
// get the HTTP binding
var b = svc.Endpoint.Binding as System.ServiceModel.BasicHttpBinding;
b.ProxyAddress = new Uri("http://127.0.0.1:8888");
b.BypassProxyOnLocal = false;
b.UseDefaultWebProxy = false;

And to set the endpoint address - where to reach the server - in code, you would do something like this:

var e = svc.Endpoint;
e.Address = new System.ServiceModel.EndpointAddress(
    "http://remoteserver:5555/WcfXmlElement");

I have had a similar problem, but I also needed to use a username and password for the proxy that differ from the username and password used to access the service.

I tried building it up through a UriBuilder, which would output the proxy address as "http://username:password@myproxyserver/". Unfortunately, the particular proxy I was using didn't work with this technique.

What I found after extensive Googling, is that you can change the proxy through WebRequest.DefaultProxy (static property).

For example:

WebProxy proxy = new WebProxy("http://myproxyserver",true);
proxy.Credentials = new NetworkCredential("username", "password");
WebRequest.DefaultWebProxy = proxy;