How to pass Request.QueryString to Url.Action?

Question

I'm building an url using the method:

Url.Action("action", "controller"); 

I like to pass the querystring for the current request into that url as well. Something like the following (but it doesn't work):

Url.Action("action", "controller", Request.QueryString); 

Converting the QueryString to routevalues is possible with the following extension:

    public static RouteValueDictionary ToRouteValues(this NameValueCollection queryString)     {         if (queryString.IsNull() || queryString.HasKeys() == false) return new RouteValueDictionary();          var routeValues = new RouteValueDictionary();         foreach (string key in queryString.AllKeys)             routeValues.Add(key, queryString[key]);          return routeValues;     } 

With the extension method the following does work:

Url.Action("action", "controller", Request.QueryString.ToRouteValues()); 

Is there an other better way ? Thx

Answer 1

If you want to easily be able to add additional route value parameters to your Url.Action, try this extension method (based on Linefeed's) which takes an anonymous object and returns a RouteValueCollection:

public static RouteValueDictionary ToRouteValues(this NameValueCollection col, Object obj) {     var values = new RouteValueDictionary(obj);     if (col != null)     {         foreach (string key in col)         {             //values passed in object override those already in collection             if (key != null && !values.ContainsKey(key)) values[key] = col[key];         }     }     return values; } 

Then you can use it like so:

Url.Action("action", "controller", Request.QueryString.ToRouteValues(new{ id=0 })); 

Answer 2

The extension method seems correct and is the way to go.