If I wish to submit a http get request using System.Net.HttpClient
there seems to be no api to add parameters, is this correct?
Yes.
Is there any simple api available to build the query string that
doesn’t involve building a name value collection and url encoding
those and then finally concatenating them?
Sure:
var query = HttpUtility.ParseQueryString(string.Empty);
query["foo"] = "bar<>&-baz";
query["bar"] = "bazinga";
string queryString = query.ToString();
will give you the expected result:
foo=bar%3c%3e%26-baz&bar=bazinga
You might also find the UriBuilder
class useful:
var builder = new UriBuilder("http://example.com");
builder.Port = -1;
var query = HttpUtility.ParseQueryString(builder.Query);
query["foo"] = "bar<>&-baz";
query["bar"] = "bazinga";
builder.Query = query.ToString();
string url = builder.ToString();
will give you the expected result:
http://example.com/?foo=bar%3c%3e%26-baz&bar=bazinga
that you could more than safely feed to your HttpClient.GetAsync
method.