Question

For paging I have this code which enables me to update the querystring without losing any elements in the querystring.

var tRVD = new RouteValueDictionary(ViewContext.RouteData.Values);

foreach (string key in Request.QueryString.Keys)
{
   tRVD[key] = Request.QueryString[key];
}

tRVD["page"] = @i;
@Html.ActionLink(@i.ToString(CultureInfo.InvariantCulture), "Index", tRVD);

I need to do the same with sorting. I have the following code but of course the querystring is overwritten by sortby. What I need is the same as I have for paging, something that just adds sortby to the querstring if it is not there and updates it if it is. How is this possible?

<form name="sortbyformtop">
   <select onchange="location.href=this.options[this.selectedIndex].value" name="sortbyselecttop">
      <option value=""></option>
      <option value="sortby=accommodationtype">Accommodation type</option>
      <option value="sortby=mostreviewed">Most reviewed</option>
      <option value="sortby=lowestprice">Lowest price</option>
   </select>
</form>

So, what I’m trying to achieve is setting the querystring to the same value as it is now plus sortby.

Answer 1

You need to add an <input type="hidden"> to your form for each value in the querystring.