如何使用Codeigniter中的form_dropdown隐藏选项值

Question

使用form_dropdown中隐藏选项标记时遇到一些问题 如何隐藏每个j_status行==关闭，然后可以隐藏选项标签
这是我的剧本

<?php
$dev='';
foreach($j as $r)
{
    if(($r->j_status)=='open')
        $dev='echo ""';
    else if(($r->j_status)=='close')
        $dev='echo hidden';
}
    echo form_dropdown("id_j",$list_jid,"default",$dev,"id='some_id'");
?>

Answer 1

<?php
$dev='';
foreach($j as $r)
{
    if(($r->j_status)=='open')
        $dev='echo ""';
    else if(($r->j_status)=='close')
        $dev='echo hidden';
echo form_dropdown("id_j",$list_jid,"default",$dev,"id='some_id'");//place here
}

?>

1. Form Helper
2. form Validation