How do I remove items from the query string for re

Question

In my base page I need to remove an item from the query string and redirect. I can't use

Request.QueryString.Remove("foo")

because the collection is read-only. Is there any way to get the query string (except for that one item) without iterating through the collection and re-building it?

Answer 1

You'd have to reconstruct the url and then redirect. Something like this:

string url = Request.RawUrl;

NameValueCollection params = Request.QueryString;
for (int i=0; i<params.Count; i++)
{
    if (params[i].GetKey(i).ToLower() == "foo")
    {
        url += string.Concat((i==0 ? "?" : "&"), params[i].GetKey(i), "=", params.Get(i));
    }
}
Response.Redirect(url);

Anyway, I didn't test that or anything, but it should work (or at least get you in thye right direction)

Answer 2

Response.Redirect(String.Format("nextpage.aspx?{0}", Request.QueryString.ToString().Replace("foo", "mangledfoo")));

I quick hack, saves you little. But foo will not be present for the code awaiting it in nextpge.aspx :)

Answer 3

Can you clone the collection and then redirect to the page with the cloned (and modified) collection?

I know it's not much better than iterating...

Answer 4

I found this was a more elegant solution

var qs = HttpUtility.ParseQueryString(Request.QueryString.ToString());
qs.Remove("item");
Console.WriteLine(qs.ToString());

Answer 5

HttpUtility.ParseQueryString(Request.Url.Query) return isQueryStringValueCollection. It is inherit from NameValueCollection.

    var qs = HttpUtility.ParseQueryString(Request.Url.Query);
    qs.Remove("foo"); 

    string url = "~/Default.aspx"; 
    if (qs.Count > 0)
       url = url + "?" + qs.ToString();

    Response.Redirect(url); 

Answer 6

Request.Url.GetLeftPart(UriPartial.Path) should do this