from query string c# code example
Example 1: get query string parameter from string value c#
Uri myUri = new Uri("http://www.example.com?param1=good¶m2=bad");
string param1 = HttpUtility.ParseQueryString(myUri.Query).Get("param1");
Example 2: string.QueryString c#
var queryString = QueryHelpers.ParseQuery("?param1=value");
// queryString.GetType() --> typeof(Dictionary<String,StringValues>)
// Adding a parameter
queryString.Add("param2", "my value"); // Easy so far.
// Adding a second parameter with the same name
queryString.Add("param2", "my other value"); // ArgumentException!
// --> An item with the same key has already been added