Rather more explanation of the context of your question might have been an idea here.
.
Cookies are a web thing and you need to be dealing with web documents ( pages ) in order to have any cookies.
You might be using a webbrowser or httpewebrequest.
Oddly enough, in windows forms it's Cookie rather than Cookies. Despite the fact it holds a collection.
https://msdn.microsoft.com/en-us/library/system.windows.forms.htmldocument.cookie%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396
var Cookies = webBrowser1.Document.Cookie;
As the docs say, cookies will be a string of key value pairs, separated by a semicolon.
So you can do something like:
string cookies = "";
httprequester.CookieContainer = new CookieContainer();
webResponse1.Cookies = httprequester.CookieContainer.GetCookies(httprequester.RequestUri);
foreach (Cookie c in httprequester.Cookies)
{
cookies += c.ToString() + ";";
}
webBrowser1.Document.Cookie = cookies;
