http://localhost/Admin/Person/index/seachkey/zhongguo
或
http://localhost/Admin/Person/index?seachkey=zhongguo
$seachkey = I('seachkey');
echo $seachkey; //结果为：zhongguo

http://localhost/Admin/Person/index?seachkey=中国
$seachkey = I('seachkey');
echo $seachkey; //结果为：中国

http://localhost/Admin/Person/index/seachkey/中国
$seachkey = I('seachkey');
echo $seachkey; //结果为空

请问谁知道这是为什么？