请教cookie为空.net报错的问题

Question

    string b="";
        string a=Request.QueryString["aa"];
        if(Request.Cookies["testCookie"].Value!=null){
             b = Request.Cookies["testCookie"].Value;
        }
        if (b== ""||b==null) {            Response.Redirect("http://baidu.com");
            Response.Write(1);
            Response.End();
        }
   if(Request.Cookies["testCookie"].Value!=null){
问题就是这句,一运行到这,就报错说空指针异常,可是我已经放在if里面了啊,怎么还报错呢
我应该怎么解决?

Answer 1

Request.Cookies["testCookie"]　！＝ null

Answer 2

Request.Cookies["testCookie"]!=null试试吧.

Answer 3

if(Request.Cookies["testCookie"]!=null)
{
   if(Request.Cookies["testCookie"].value!=null)
    {
         .....
    }
}

Answer 4

  这样才对：
string b="";
        string a=Request.QueryString["aa"];
        if(Request.Cookies["testCookie"]!=null){
             b = Request.Cookies["testCookie"].Value;
        }
        if (b== ""||b==null) {            Response.Redirect("http://baidu.com");
            Response.Write(1);
            Response.End();
        }