Get Url Parameters from a String In. Net

This is probably what you want

var uri = new Uri("");
var query = HttpUtility.ParseQueryString(uri.Query);

var var2 = query.Get("var2");

Here's another alternative if, for any reason, you can't or don't want to use HttpUtility.ParseQueryString().

This is built to be somewhat tolerant to "malformed" query strings, i.e. becomes a parameter with an empty value. The caller can verify the parameters if needed.

public static class UriHelper
{
    public static Dictionary<string, string> DecodeQueryParameters(this Uri uri)
    {
        if (uri == null)
            throw new ArgumentNullException("uri");

        if (uri.Query.Length == 0)
            return new Dictionary<string, string>();

        return uri.Query.TrimStart('?')
                        .Split(new[] { '&', ';' }, StringSplitOptions.RemoveEmptyEntries)
                        .Select(parameter => parameter.Split(new[] { '=' }, StringSplitOptions.RemoveEmptyEntries))
                        .GroupBy(parts => parts[0],
                                 parts => parts.Length > 2 ? string.Join("=", parts, 1, parts.Length - 1) : (parts.Length > 1 ? parts[1] : ""))
                        .ToDictionary(grouping => grouping.Key,
                                      grouping => string.Join(",", grouping));
    }
}

Test

[TestClass]
public class UriHelperTest
{
    [TestMethod]
    public void DecodeQueryParameters()
    {
        DecodeQueryParametersTest("", new Dictionary<string, string>());
        DecodeQueryParametersTest("", new Dictionary<string, string>());
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "key", "bla/blub.xml" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "eins", "1" }, { "zwei", "2" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "empty", "" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "empty", "" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "key", "1" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "key", "value?" }, { "b", "c" } });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "key", "value=what" } });
        DecodeQueryParametersTest("",
            new Dictionary<string, string>
            {
                { "q", "energy+edge" },
                { "rls", "com.microsoft:en-au" },
                { "ie", "UTF-8" },
                { "oe", "UTF-8" },
                { "startIndex", "" },
                { "startPage", "1%22" },
            });
        DecodeQueryParametersTest("", new Dictionary<string, string> { { "key", "value,anotherValue" } });
    }

    private static void DecodeQueryParametersTest(string uri, Dictionary<string, string> expected)
    {
        Dictionary<string, string> parameters = new Uri(uri).DecodeQueryParameters();
        Assert.AreEqual(expected.Count, parameters.Count, "Wrong parameter count. Uri: {0}", uri);
        foreach (var key in expected.Keys)
        {
            Assert.IsTrue(parameters.ContainsKey(key), "Missing parameter key {0}. Uri: {1}", key, uri);
            Assert.AreEqual(expected[key], parameters[key], "Wrong parameter value for {0}. Uri: {1}", parameters[key], uri);
        }
    }
}

Looks like you should loop over the values of myUri.Query and parse it from there.

 string desiredValue;
 foreach(string item in myUri.Query.Split('&'))
 {
     string[] parts = item.Replace("?", "").Split('=');
     if(parts[0] == "desiredKey")
     {
         desiredValue = parts[1];
         break;
     }
 }

I wouldn't use this code without testing it on a bunch of malformed URLs however. It might break on some/all of these:

• hello.html?
• hello.html?valuelesskey
• hello.html?key=value=hi
• hello.html?hi=value?&b=c
• etc

@Andrew and @CZFox

I had the same bug and found the cause to be that parameter one is in fact: and not param1 which is what one would expect.

By removing all characters before and including the question mark fixes this problem. So in essence the HttpUtility.ParseQueryString function only requires a valid query string parameter containing only characters after the question mark as in:

HttpUtility.ParseQueryString ( "param1=good&param2=bad" )

My workaround:

string RawUrl = "";
int index = RawUrl.IndexOf ( "?" );
if ( index > 0 )
    RawUrl = RawUrl.Substring ( index ).Remove ( 0, 1 );

Uri myUri = new Uri( RawUrl, UriKind.RelativeOrAbsolute);
string param1 = HttpUtility.ParseQueryString( myUri.Query ).Get( "param1" );`

You can just use the Uri to get the list of the query strings or find a specific parameter.

Uri myUri = new Uri("");
var params = myUri.ParseQueryString();
var specific = myUri.ParseQueryString().Get("spesific");
var paramByIndex = = myUri.ParseQueryString().Get(1);

You can find more from here:

You can use the following workaround for it to work with the first parameter too:

var param1 =
    HttpUtility.ParseQueryString(url.Substring(
        new []{0, url.IndexOf('?')}.Max()
    )).Get("param1");

Or if you don't know the URL (so as to avoid hardcoding, use the AbsoluteUri

Example ...

        //get the full URL
        Uri myUri = new Uri(Request.Url.AbsoluteUri);
        //get any parameters
        string strStatus = HttpUtility.ParseQueryString(myUri.Query).Get("status");
        string strMsg = HttpUtility.ParseQueryString(myUri.Query).Get("message");
        switch (strStatus.ToUpper())
        {
            case "OK":
                webMessageBox.Show("EMAILS SENT!");
                break;
            case "ER":
                webMessageBox.Show("EMAILS SENT, BUT ... " + strMsg);
                break;
        }

Use .NET Reflector to view the FillFromString method of System.Web.HttpValueCollection. That gives you the code that ASP.NET is using to fill the Request.QueryString collection.

Single line LINQ solution:

Dictionary<string, string> ParseQueryString(string query)
{
    return query.Replace("?", "").Split('&').ToDictionary(pair => pair.Split('=').First(), pair => pair.Split('=').Last());
}

if you want in get your QueryString on Default page .Default page means your current page url . you can try this code :

string paramIl = HttpUtility.ParseQueryString(this.ClientQueryString).Get("city");

This is actually very simple, and that worked for me :)

        if (id == "DK")
        {
            string longurl = "selectServer.aspx?country=";
            var uriBuilder = new UriBuilder(longurl);
            var query = HttpUtility.ParseQueryString(uriBuilder.Query);
            query["country"] = "DK";

            uriBuilder.Query = query.ToString();
            longurl = uriBuilder.ToString();
        } 

For anyone who wants to loop through all query strings from a string

        foreach (var item in new Uri(urlString).Query.TrimStart('?').Split('&'))
        {
            var subStrings = item.Split('=');

            var key = subStrings[0];
            var value = subStrings[1];

            // do something with values
        }

HttpContext.Current.Request.QueryString.Get("id");