Set query parameter based on current URL - asp.net

Question

I am working on a standard paging component for my project. All controllers with paging are waiting for PageIndex parameter in URL.
So I want to generate URL based on the current URL except for the PageIndex parameter.
For example, I have filters for my internet store like Manufacturer and MaxPrice.
A user opens the mystore.com/products?manufacturer=Apple&MaxPrice=999 link.
Then he wants to go to the 3 pages. So the 3-page link in my paging should have the mystore.com/products?manufacturer=Apple&MaxPrice=999&PageIndex=3 link.
So needed MVC function should:
Persists all existing params like MaxPrice and manufacturer
Replace only PageIndex param
don't use any hardcoded controller and action values (like controller = 'Products', Action = 'Index')
I try to use this code:
<a class="page-link" href="#Url.RouteUrl(new { PageIndex = page })">
#page
</a>
It works fine except the 2 rule - it doesn't persist other arguments.
So if user click on this link he goes to mystore.com/products?PageIndex=3

Answer 1

I suggest to build the url dynamically by getting currentUrl with query strings "Request.Url.AbsoluteUri" then remove the pageIndex from url if exists , then add page index again.
hint : url must be defined as variable in your razor to make the things easier
To remove query string you can use regex
string queryString = "Default.aspx?Agent=10&Language=2"; //Request.QueryString.ToString();
string parameterToRemove="Language"; //parameter which we want to remove
string regex=string.Format("(&{0}=[^&\s]+|{0}=[^&\s]+&?)",parameterToRemove);
string finalQS = Regex.Replace(queryString, regex, "");

Answer 2

You can use these to get the current url
string url = HttpContext.Current.Request.Url.AbsoluteUri;
// http://localhost:1302/TEST/Default.aspx
string path = HttpContext.Current.Request.Url.AbsolutePath;
// /TEST/Default.aspx
And then you can add the page index like this and redirect to that url
url = url+"&PageIndex=3";
Recommended
Or you can get the url parameters with
#Url.RequestContext.RouteData.Values["manufacturer"]
#Url.RequestContext.RouteData.Values["MaxPrice"]
And use those values to build the new URL inside the View