开启邀请码注册：
进入站点后台->全局->注册与访问，找到允许新用户注册，勾选开放邀请注册方式。

代码分析：
找到source\class\class_member.php文件，在336行附近
 

$invitestatus = false;  
                if($this->setting['regstatus'] == 2) {  
                        if($this->setting['inviteconfig']['inviteareawhite']) {  
                                $location = $whitearea = '';  
                                $location = trim(convertip($_G['clientip'], "./"));  
                                if($location) {  
                                        $whitearea = preg_quote(trim($this->setting['inviteconfig']['inviteareawhite']), '/');  
                                        $whitearea = str_replace(array("\\*"), array('.*'), $whitearea);  
                                        $whitearea = '.*'.$whitearea.'.*';  
                                        $whitearea = '/^('.str_replace(array("\r\n", ' '), array('.*|.*', ''), $whitearea).')$/i';  
                                        if(@preg_match($whitearea, $location)) {  
                                                $invitestatus = true;  
                                        }  
                                }  
                        }  
 
                        if($this->setting['inviteconfig']['inviteipwhite']) {  
                                foreach(explode("\n", $this->setting['inviteconfig']['inviteipwhite']) as $ctrlip) {  
                                        if(preg_match("/^(".preg_quote(($ctrlip = trim($ctrlip)), '/').")/", $_G['clientip'])) {  
                                                $invitestatus = true;  
                                                break;  
                                        }  
                                }  
                        }  
                }