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HttpUtility.UrlDecode or unescape in asp.net (c#)

I have a flash that contains links to userprofiles on my asp.net pages. Since I live in Norway some usernames contains some norwegian characters like "æ, ø, å". It the username is "øyvind", the flash links to the profile page like this:

User.aspx?user=%D8yvind

The problem is that my asp.net code don't understand this encoding. If I in asp.net use server.urlencode("øyvind") it looks like this: User.aspx?user=%c3%98yvind. I guess that's why server.urldecode don't understand this querystring parameter.

I have tried so many things, but can't get asp.net to read "%D8yvind" so that it becomes like "øyvind" in my code.

The developers that made the flash say I can use "unescape" to solve this. I have tried this, but no luck when using Request.QueryString["user"]:

string userName = Request.QueryString["user"]; // it don't works when using request.querystring!
//string userName = "%D8yvind"; // this works!

string user = HttpUtility.UrlDecode(userName, System.Text.Encoding.);
Response.Write(user);

Result when reading "user" from querystring is: ¿yvind (should be: øyvind)

Thanks for all help!!!

SprudeVI

In unicode, there are several representations for the same glyph, e.g. there is a code for "ø" but the same glyph can be generated with two characters (special "/" + "o") in order to convert from one representation to another you have to "normalize" the string (just google "normalize unicode", and you will find e.g. http://msdn.microsoft.com/en-us/library/dd374126(VS.85).aspx). In .NET you can do something like this:

string name = "øyvind";
name = name.Normalize(NormalizationForm.FormKC;

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webressurs

ASKER

Thanks for your reply!

Did you mean something like this:

//user.aspx?user=%F8yvind

string userName = Request.QueryString["user"];
string user = userName.Normalize(System.Text.NormalizationForm.FormKC);
user = HttpUtility.UrlDecode(user, System.Text.Encoding.Default);
Response.Write(user);

It still don't works, the result is "¿yvind" (not "øyvind").

Any clue?

SprudeVI

Did you try different values from "NormalizationForm"? "FormKC" was the one that I had in my head, but I always mix them up.

webressurs

ASKER

Yes, I have tried all the values from NormalizationForm. This is another person with the same problem, but not solved: http://www.velocityreviews.com/forums/t633225-decode-url-string.html

There has to be one way to encode url parameters like this in asp.net C#:
www.website.com?test=%F8%E5%C6%D8%C5

SprudeVI

URL encoding should be unicode, but it doesn't have to. Your flash program seems to use the "latin1" encoding (formal name "ISO 8859-1", cf. http://en.wikipedia.org/wiki/ISO/IEC_8859-1).

The following program prints "øåÆØÅ" to the console.

If this is the solution, it would be better to change your flash program to Unicode (e.g. UTF-8) for minimal i18n problems, instead of changing your C# program which assumes unicode by default.

using System;
using System.Text;
using System.Web;

class Test
{
    static void Main(string[] args)
    {
        string username = "%F8%E5%C6%D8%C5";
        Encoding enc = Encoding.GetEncoding("iso-8859-1");
        Console.WriteLine(HttpUtility.UrlDecode(username, enc));
        Console.ReadKey();
    }
}

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SprudeVI

Use this program to compare all the encodings:

using System;
using System.Text;
using System.Web;

class Test
{
    static void Main(string[] args)
    {
        string username = "%F8yvind";
        foreach (EncodingInfo ei in Encoding.GetEncodings()) {
            Console.WriteLine(ei.Name + ":" + ei.CodePage);
            Encoding enc = ei.GetEncoding();
            Console.WriteLine(HttpUtility.UrlDecode(username, enc));
        }
        Console.ReadKey();
    }
}

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webressurs

ASKER

Hello, thanks for your reply :)

The thing is that it works if I set the string = %F8yvind directly.
But, if I use Request.Querystring it don't works.

//Works using this:
string userName = "%F8yvind";

//Fails using this:
string userName = Request.QueryString["user"];

System.Text.Encoding enc = System.Text.Encoding.GetEncoding("iso-8859-1");
Response.Write(HttpUtility.UrlDecode(userName, enc));

Hmmm... ? :)

SprudeVI

So what is the query string? If you print out Request.QueryString["user"] without decoding it, does the "%F8yvind" arrive, or do you get something else?

SprudeVI

Did you try this as well?

string username = Request.QueryString["user"];
foreach (EncodingInfo ei in Encoding.GetEncodings()) {
    Response.Write(ei.Name + ":" + ei.CodePage + ":");
    Encoding enc = ei.GetEncoding();
    Response.Write(HttpUtility.UrlDecode(username, enc) + "<br>");
}

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webressurs

ASKER

The querystring is like this: test.aspx?user=%F8yvind

If I print out Request.QueryString["user"] without decoding it, "%F8yvind" does not arrive like the querystring. Instead of getting "%F8" I just get a "square" symbol.

When trying the loop, every single decoding has the square symbol instead og "ø".

ASKER CERTIFIED SOLUTION

SprudeVI

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webressurs

ASKER

Seems like this is the only way to solve it:

//Get query and removes "user=" from url
string queryUser = Request.ServerVariables["QUERY_STRING"].Substring(5);

//Encoding
string user = HttpUtility.UrlDecode(queryUser, System.Text.Encoding.Default);

Response.Write(user);

SOLUTION

SprudeVI

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