Question

I need to check if there is a param on the uri request.

So I need to check if that param is set. Is there a function on .NET/C#?

Answer 1

An unset value will be null or empty:

value = Request["param"];
if (String.IsNullOrEmpty(value))
{
    // param is not set
}

If the param name is in the query string but the value is not, it will be empty. If the name is not in the query string, the value will be null. For example.

&param1=&param2=value 
// Request["param1"] is String.Empty
// Request["param3"] is null