Wordpress管理员搜索不返回自定义字段的自定义帖子类型的结果

Question

因此，我使用自定义字段定义了“客户”类型的自定义帖子类型，如下所示：

// Clients
register_post_type( 'isa_client',
    array(
        'labels' => array(
            'name' => __( 'Clients' ),
            'singular_name' => __( 'Client' )
        ),
    'public' => true,
    'has_archive' => true,
    'hierarchical' => false,
    'show_ui' => true,
    'show_in_menu' => 'mnuIsAppointments',
    'rewrite' => true,
    'supports' => array('thumbnail') 
    )
);

并且还指定了在admin客户端页面上显示的列，如下所示：

add_filter("manage_edit-isa_client_columns", "isa_client_edit_columns"); 

function isa_client_custom_columns($column){  
        global $post;  
        switch ($column)  
        {  
            case "isa_client_salutation":  
                $custom = get_post_custom();  
                echo "<b><a href=" . get_edit_post_link($post->id) . ">" . $custom["isa_client_salutation"][0] . " " . $custom["isa_client_name"][0] . " " . $custom["isa_client_surname"][0] . "</a></b>";
                break; 
            case "isa_client_phone":  
                $custom = get_post_custom();  
                echo $custom["isa_client_phone"][0];
                break; 
            case "isa_client_email":  
                $custom = get_post_custom();  
                echo $custom["isa_client_email"][0];
                break; 
            case "isa_client_address":  
                $custom = get_post_custom();  
                echo $custom["isa_client_address"][0];
                break; 
        }  
}  

但是，当尝试使用自定义字段值搜索客户端时，我没有得到任何结果