How to check if an 'unknown' parameter is supplied in a Request's Query String?

Question

For example, if a query string has 2 expected parameters , say. param1 = "abc" & param2 = "def".

I know that Request.QuerySring["abc"] will check for "abc" in query string.

But is there any way to validate if user enters anything else other than param1 or param2?

Thanks.

Why do you care? if the user enters a value with an identifier that you don't use in your code, then it's meaningless anyway. — Zohar Peled, Aug 26 '15 at 04:45
http://stackoverflow.com/questions/2375372/is-there-a-way-to-get-all-the-querystring-name-value-pairs-into-a-collection — JleruOHeP, Aug 26 '15 at 04:46

score 3 · Accepted Answer · answered Aug 26 '15 at 04:49

Yes, you can use AllKeys:

Request.QueryString.AllKeys

To get the list of parameters used apart from 'param1' and 'param2':

var expectedParams = new [] { "param1", "param2" };
var additionalParams = Request.QueryString.AllKeys.Where(k => !expectedParams.Contains(k));

score 0 · Answer 2 · answered Aug 26 '15 at 04:50

If you try to retrieve Request.QuerySring["param1"] you will get the value abc. Now if the user change the KEYS of the query-string you will not able receive it as your are retrieving the query-string values by KEYS. So you dont need to validate users inputs.

How to check if an 'unknown' parameter is supplied in a Request's Query String?

2 Answers2