c＃如何检查QueryString Values count是否与key的数量具有相同的值

Question

Here is my problem:

If my url has QueryString ?asdasdafa I can handle it with : if(HttpContext.Current.Request.QueryString.HasKeys())

But if my url has QueryString ?asdasasfasdas&brand=Sony then it will fail with null exception because is actually has one key, and the other one doesn't have it. Is there an easy way to check

if(HttpContext.Current.Request.QueryString.KeysCount ==
HttpContext.Current.Request.QuesryString.ValuesCount))

Answer 1

I don't think you need to do that, doing a simple null check will suffice

if(Request.QueryString["asdasdafa"]==null)
{
   // value missing
}

The fact that asdasdafa is not even included as one of the keys on the QueryString won't make your application throw an Exception.

EDIT

Based on the comment, you could then walk through the keys present as so:

foreach (var item in Request.QueryString.AllKeys)
{
   if (Request.QueryString[item] == null)
                //value missing

}

Answer 2

When I run your 2nd example, HttpContext.Current.Request.QueryString.HasKeys() doesn't fail for me, and asdasasfasdas is the first value I get, but its key is null . You can check if the key is null by

NameValueCollection nvc = Context.Request.QueryString;
if (nvc.GetKey(0) == null){}

Answer 3

I am not sure whether HasKeys can handle that, If not,how about writing your own extension method / override the HasKeys() ?. Read the querystring in that method and split it with & and then again with = on each items of the first split result. Then return Yes or No

Answer 4

I haven't tested this so I don't know if it works, but you could try checking against these counts:

int keys = Request.QueryString.Keys.Count;
int args = Request.QueryString.Count;

if (keys != args) ...