Can I automatically remove a parameter on querystring with Request.Url.Query?

Question

When I get the querystring with Request.Url.Query I'd like to exclude a parameter (without using replace, or function like these).

So, for example, if I have this querystring :

?ID=1241&IDL=241&HC=1241

I'd like to exclude IDL getting :

?ID=1241&HC=1241

Is this a implemented way or I need to make my own function?

EDIT : I care about the order of my query string values.

Do you mean replace the Query property in the Uri object to "fool downstream" or just getting a string not including it? — Joachim Isaksson
– Joachim Isaksson, Commented Jan 19, 2012 at 16:50
not including it...! Also because I don't know what do you mean with "fool downstream" :) — markzzz
– markzzz, Commented Jan 19, 2012 at 16:50
@markzzz I think he means "do you want other calls of Request.Url.Query later on to beleive that the query string value isn't there?" — vcsjones
– vcsjones, Commented Jan 19, 2012 at 16:54
The querystring cannot be modified. but you can parse it (it's a KeyValuePair collection) and modify the collection, and then restore it back (via a Response.Redirect("page.aspx?" + modifiedQS)) — Oxonhammer
– Oxonhammer, Commented Jan 19, 2012 at 16:55
on a side note, caring about the order of query string params doesn't sound right to me — Alex
– Alex, Commented Jan 20, 2012 at 13:02

Dave Watts · Accepted Answer · 2012-01-23 11:28:32Z

4

It's still string manipulation, but how about something like:

String.Concat("?",
    String.Join("&",
        Request.Url.Query.Substring(1)
            .Split('&')
            .Where(k => !k.StartsWith("IDL="))
            .ToArray() // For .NET versions prior to v4.0
     )
)

Alternatively you could use Request.QueryString to get at a processed collection of query-string parameters.

EDIT: This will leave your parameters in the order they were sent.

Here's a sample ASPX page that outputs a modified query-string (I've tested it in a ASP.NET 3.5 Web-Site):

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<%@ Import Namespace="System.Linq" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Query String Removal</title>
</head>
<body>
    Modified query-string: <%=
        String.Concat("?",
            String.Join("&",
                Request.Url.Query.Substring(1)
                    .Split('&')
                    .Where(k => !k.StartsWith("IDL="))
                    .ToArray() // For .NET versions prior to v4.0
             )
        )
    %>
</body>
</html>

NOTE: System.Linq has been imported. An exception will be raised if you don't specify a query-string.

edited Jan 23, 2012 at 11:28

answered Jan 19, 2012 at 17:01

Dave Watts

8907 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

markzzz Over a year ago

And from this can I remove directly a parameter?

Dave Watts Over a year ago

I take it you mean from the Request.QueryString collection, I'm afraid not, it's a read-only collection :-[, as mentioned by Oxonhammer.

markzzz Over a year ago

added (string[]) before Request.Url.Query...., but now it says System.InvalidCastException: Impossibile eseguire il cast di oggetti di tipo 'WhereArrayIterator1[System.String]' sul tipo 'System.String[]'.`

Dave Watts Over a year ago

What version of .NET are you using? The code I posted I tried in a .NET ASP.NET web-site.

Dave Watts Over a year ago

^^ .NET 4.0 ASP.NET web-site. I've tweaked the code for prior versions of .NET, I haven't tested it though.

|

Mikael Engver · Accepted Answer · 2014-01-27 10:49:26Z

2

I used this which can be called multiple times if you have a list of keys that you want removed from the querystring if they exists:

private string RemoveQueryStringItemWithKeyName(string url, string keyName)
{
    var urlItemRemoved = String.Join("&", url.Split('&').Where(k => !k.StartsWith(keyName + "=")));
    return urlItemRemoved;
}

answered Jan 27, 2014 at 10:49

Mikael Engver

4,7884 gold badges50 silver badges56 bronze badges

Collectives™ on Stack Overflow

Can I automatically remove a parameter on querystring with Request.Url.Query?

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related