Sharepoint Redirecting from 1 page to another

string url = "~remoteAppUrl/Pages/PollQuestionView.aspx";

string queryString = "SPHostUrl=http%3a%2f%2fspmain%3a3865&SPLanguage=en??-US&SPClientTag=0&SPProductNumber=15.0.4420.1017";

SPUtility.Redirect(url, SPRedirectFlags.Default, Context, queryString);