Get individual query parameters from Uri

Question

I have a uri string like: http://example.com/file?a=1&b=2&c=string%20param

Is there an existing function that would convert query parameter string into a dictionary same way as ASP.NET Context.Request does it.

I'm writing a console app and not a web-service so there is no Context.Request to parse the URL for me.

I know that it's pretty easy to crack the query string myself but I'd rather use a FCL function is if exists.

Answer 1

Use this:

string uri = ...;
string queryString = new System.Uri(uri).Query;
var queryDictionary = System.Web.HttpUtility.ParseQueryString(queryString);

This code by Tejs isn't the 'proper' way to get the query string from the URI:

string.Join(string.Empty, uri.Split('?').Skip(1));

Answer 2

You can use:

var queryString = url.Substring(url.IndexOf('?')).Split('#')[0]
System.Web.HttpUtility.ParseQueryString(queryString)

MSDN

Answer 3

This should work:

string url = "http://example.com/file?a=1&b=2&c=string%20param";
string querystring = url.Substring(url.IndexOf('?'));
System.Collections.Specialized.NameValueCollection parameters = 
   System.Web.HttpUtility.ParseQueryString(querystring);

According to MSDN. Not the exact collectiontype you are looking for, but nevertheless useful.

Edit: Apparently, if you supply the complete url to ParseQueryString it will add 'http://example.com/file?a' as the first key of the collection. Since that is probably not what you want, I added the substring to get only the relevant part of the url.

Answer 4

I had to do this for a modern windows app. I used the following:

public static class UriExtensions
{
    private static readonly Regex _regex = new Regex(@"[?&](\w[\w.]*)=([^?&]+)");

    public static IReadOnlyDictionary<string, string> ParseQueryString(this Uri uri)
    {
        var match = _regex.Match(uri.PathAndQuery);
        var paramaters = new Dictionary<string, string>();
        while (match.Success)
        {
            paramaters.Add(match.Groups[1].Value, match.Groups[2].Value);
            match = match.NextMatch();
        }
        return paramaters;
    }
}

Answer 5

For isolated projects, where dependencies must be kept to a minimum, I found myself using this implementation:

var arguments = uri.Query
  .Substring(1) // Remove '?'
  .Split('&')
  .Select(q => q.Split('='))
  .ToDictionary(q => q.FirstOrDefault(), q => q.Skip(1).FirstOrDefault());

Do note, however, that I do not handle encoded strings of any kind, as I was using this in a controlled setting, where encoding issues would be a coding error on the server side that should be fixed.

Answer 6

Have a look at HttpUtility.ParseQueryString() It'll give you a NameValueCollection instead of a dictionary, but should still do what you need.

The other option is to use string.Split().

    string url = @"http://example.com/file?a=1&b=2&c=string%20param";
    string[] parts = url.Split(new char[] {'?','&'});
    ///parts[0] now contains http://example.com/file
    ///parts[1] = "a=1"
    ///parts[2] = "b=2"
    ///parts[3] = "c=string%20param"

Answer 7

In a single line of code:

string xyz = Uri.UnescapeDataString(HttpUtility.ParseQueryString(Request.QueryString.ToString()).Get("XYZ"));

Answer 8

Microsoft Azure offers a framework that makes it easy to perform this. http://azure.github.io/azure-mobile-services/iOS/v2/Classes/MSTable.html#//api/name/readWithQueryString:completion:

Answer 9

You could reference System.Web in your console application and then look for the Utility functions that split the URL parameters.