Stop webclient from escaping strings

Question

I want to use the Google Maps API to geocode/reverse-geocode coordinates/addresses. To do this, I use an instance of C#'s webclient class.

static string gMapsUrl= "http://maps.googleapis.com/maps/api/geocode/xml?address=  {0}&sensor=false";
public static List<Location> RetrieveCoordinate(string address)
{
    string requestUri = string.Format(gMapsUrl, address);
    string result = string.Empty;

    using (var client = new WebClient())
    {
        client.Encoding = System.Text.Encoding.UTF8;
        result = client.DownloadString(requestUri);
    }
....
}

This usually works, however lets say I want to reverse-geocode the address "Götznerstraße". If I do this manually in a browser, everything works fine, the URL of the request would be

http://maps.googleapis.com/maps/api/geocode/xml?address=götznerstraße&sensor=false

The eventual request from my program however looks like this

GET /maps/api/geocode/xml?address=G%C3%B6tznerstra%C3%9Fe&sensor=false HTTP/1.1

This leads to Google finding no matches. To me it appears as if the webclient escapes the umlaute somewhere, which prevents me from getting results. Is there a way to stop the webclient from doing this, or make Google unescape the string again?

EDIT: I solved it, after comparing the request from the browser and my program, I realized that my browser was sending some additional headers. The changed implementation looks like this

using (var client = new WebClient())
{
    client.Headers.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
    client.Headers.Add("Accept-Encoding", "gzip,deflate,sdch");
    client.Headers.Add("Accept-Language", "de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4");
    client.Encoding = System.Text.Encoding.UTF8;
    result = client.DownloadString(requestUri);
}

Thanks a lot to everyone that helped!

Probably the browser is just automatically translating it back to you to make it more readable. — Uwe Keim, Jan 27 '14 at 07:55
If you open the developer mode in your browser of choice (e.g. Ctrl+shift+I on Chrome), you'll see that the URL in the actual HTTP GET request is always percent-encoded. I would use [Fiddler](http://www.telerik.com/fiddler) and compare actual HTTP requests of a working browser and your app. — vgru, Jan 27 '14 at 08:03
Thanks to both of you Uwe and Groo, I compared the two requests and saw that the request my program made was missing some headers! — user3239482, Jan 27 '14 at 08:11

score 2 · Accepted Answer · edited May 23 '17 at 10:31

2

It has to escape the url. However there is nothing stopping you from using HttpUtility.UrlDecode to unescape it. Also have a look here for a more indepth answer.

edited May 23 '17 at 10:31

Community

1
1

answered Jan 27 '14 at 07:52

Alex

1,110
8
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2

URL encoding rules and HTML encoding rules are not precisely the same. If you want to decode a URL, use `UrlDecode`, not `HtmlDecode`. – Damien_The_Unbeliever Jan 27 '14 at 07:53
You are right. My bad, copypasted without reading my own answer :) Thx Damien. – Alex Jan 27 '14 at 08:25

score 0 · Answer 2 · answered Jan 27 '14 at 07:54

0

I think the problem is actually just that Google doesn't quite know what to do with götznerstraße.

Google doesn't know götznerstraße

do you actually mean götzner straße?

Regardless, G%C3%B6tznerstra%C3%9Fe is the correct encoding of "götznerstraße", and the encoding is not causing your issue.

answered Jan 27 '14 at 07:54

Mitch

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Did you try entering OP's example url in the browser? Because the [unescaped version](http://maps.googleapis.com/maps/api/geocode/xml?address=götznerstraße&sensor=false) works ok on my machine. – vgru Jan 27 '14 at 07:58
I did, actually, it gives "INVALID_REQUEST" for me. Perhaps it is a geographic issue. – Mitch Jan 27 '14 at 08:00

Stop webclient from escaping strings

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