using System.Collections.Generic;

IDictionary<string, string> Dict_query = new Dictionary<string, string>();

 foreach (string key in Request.QueryString.Keys)
        {
            Dict_query[key] =Text.killURLattack(Request.QueryString[key]);
        }

RQ_ID1 = Dict_query["ID1"];
RQ_linkMdb = Dict_query["linkMdb"];

判断：

if (Dict_query.ContainsKey("ID2")) //判断是否有ID2的参数提交上来
        {
            RQ_ID2 = Dict_query["ID2"];
        }