Question

I need to consume a service that takes a GET parameter named “names[]”.

For example: GET http://example.com/name2id?names[]=john

When I try to consume that in C# using a WebClient, the brackets gets encoded to %5B%5D, which the servies does not understand. When I send the above using my browser (un-encoded), everything works fine.

Heres the example that does not work:

using (var client = new System.Net.WebClient())
{
    response = client.DownloadString(new Uri("http://example.com/name2id?names[]=john"));
}

Monitored by fiddler, heres the request:

GET http://example.com/name2id?names%5B%5D=john HTTP/1.1
Host: example.com
Connection: Keep-Alive

Is there any way to make the framework NOT encode the URL, or some other way around this issue?

P.S. I do not control the API so I cannot change that.

UPDATE:

This is kinda wierd. I found a solution, changing my C# code to:

using (var client = new System.Net.WebClient())
{
    response = client.DownloadString(new Uri("http://example.com/name2id?names[]=john", true));
}

Note the boolean dontEscape in Uri. It is actually deprecated, but it works? Can anyone explain this?

Answer 1

As mentioned by CodeInChaos, the URL is not valid according to RFC2396.

To make C# not escape invalid characters, the overloaded method of URI can be usen:

new Uri("http://example.com/name2id?names[]=john", true)

However, this method is deprecated but apparently it still works. I have to live with the warning popping up 🙂