Question

If I call

var nvc = HttpUtility.ParseQueryString("?foo=bar&baz=robots")

I get back a NameValueCollection where if I call ToString on it, I get back a query string.

var str = nvc.ToString(); //foo=bar&baz=robots....

If I create a new NameValueCollection, add stuff to it, and call ToString() on it, I don’t get back a query string.

var nvc= new NameValueCollection();
nvc["foo"] = "bar";
var str = nvc.ToString(); //default for Object.ToString()

Also there doesn’t seem to be a way to construct a NameValueCollection that acts as a query string editor. Is there one? If not, why? Being able to edit query strings is a pretty useful thing, but this functionality is totally hidden away in an obscure mode of some object most people don’t even know exists.

Answer 1

This is done by the internal HttpValueCollection class, which inherits NameValueCollection and overrides ToString().
ParseQueryString() is the only public way to construct this class.