php iconv() : Detected an illegal character in input string

开始是这样用的$str = iconv(‘UTF-8’, ‘GB2312’, unescape(isset($_GET[‘str’])? $_GET[‘str’]:”));上线后报一堆这样的错：iconv() : Detected an illegal character in input string考虑到GB2312字符集比较小，换个大的吧，于是改成GBK：$str = iconv(‘UTF-8’, ‘GBK’, unescape(isset($_GET[‘str’])? $_GET[‘str’]:”));上线后还是报同样的错！再认真读手册，发现有这么一段：If you append th