System.Net.Http.FormUrlEncodedContent

public class FormUrlEncodedContent : ByteArrayContent

A container for name/value tuples encoded using application/x-www-form-urlencoded MIME type.

public FormUrlEncodedContent(IEnumerable<KeyValuePair<string, string>> nameValueCollection)

Initializes a new instance of the FormUrlEncodedContent class with a specific collection of name/value pairs.