Replace item in querystring

Question

I have a URL that also might have a query string part, the query string might be empty or have multiple items.

I want to replace one of the items in the query string

Answer 1

I use following method:

    public static string replaceQueryString(System.Web.HttpRequest request, string key, string value)
    {
        System.Collections.Specialized.NameValueCollection t = HttpUtility.ParseQueryString(request.Url.Query);
        t.Set(key, value);
        return t.ToString();
    }

Answer 2

I agree with Cerebrus. Sticking to the KISS principle, you have the querystring,

string querystring = myURI.Query; 

you know what you are looking for and what you want to replace it with.

So use something like this:-

if (querystring == "") 
  myURI.Query += "?" + replacestring; 
else 
  querystring.replace (searchstring, replacestring); // not too sure of syntax !!

Answer 3

I found this was a more elegant solution

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

Answer 4

You can speed up RegExps by precompiling them.

Check out this tutorial

Answer 5

string link = page.Request.Url.ToString();

if(page.Request.Url.Query == "")
    link  += "?pageIndex=" + pageIndex;
else if (page.Request.QueryString["pageIndex"] != "")
{
    var idx = page.Request.QueryString["pageIndex"];
    link = link.Replace("pageIndex=" + idx, "pageIndex=" + pageIndex);
}
else 
    link += "&pageIndex=" + pageIndex;

This seems to work really well.

Answer 6

Lets have this url: https://localhost/video?param1=value1

At first update specific query string param to new value:

var uri = new Uri("https://localhost/video?param1=value1");
var qs = HttpUtility.ParseQueryString(uri.Query);
qs.Set("param1", "newValue2");

Next create UriBuilder and update Query property to produce new uri with changed param value.

var uriBuilder = new UriBuilder(uri);
uriBuilder.Query = qs.ToString();
var newUri = uriBuilder.Uri;

Now you have in newUri this value: https://localhost/video?param1=newValue2