升级php7.1.*后phpcms V9编辑文章出错的解决方法

function get_keyword($str,$ilen=-1) {
 if($str=='') return '';
 else $this->split_result($str,true,true);
 $okstr = $this->result_string;
 $ws = explode(' ',$okstr);
 $okstr = $wks = '';
 foreach($ws as $w) {
 $w = trim($w);
 if(strlen($w)<2) continue;
 if(!preg_match("/[^0-9:-]/",$w)) continue;
 if(strlen($w)==2&&ord($w[0])>0x80) continue;
 if($wks=="") $wks=array();
 if(isset($wks[$w])) $wks[$w]++;
 else $wks[$w] = 1; //345行的内容
 }
 if(is_array($wks)) {
 arsort($wks);
 if($ilen==-1) {
 foreach($wks as $w=>$v) {
 if($this->get_rank($w)>500) $okstr .= $w." ";
 }
 } else {
 foreach($wks as $w=>$v){
 if((strlen($okstr)+strlen($w)+1)<$ilen) $okstr .= $w." ";
 else break;
 }
 }
 }