我正在尝试创建自己的自定义字段元框，只在页面中填充复选框。我是以它为基础的this tutorial here. 我可以让原来的教程正常工作，但当我开始简化它，只保存一个复选框时，它停止了工作：当我更新页面时，复选框不会保存“打开”状态。

我确信这与函数的保存部分有关。有人有任何线索、提示或提示吗？谢谢

<?php function cd_meta_box_cb() { 
// Some settings first:
    global $post;
    $check = isset( $values[\'page_title_off\'] ) ? esc_attr( $values[\'page_title_off\'][0] ) : \'\';    
    // We\'ll use this nonce field later on when saving.
    wp_nonce_field( \'my_meta_box_nonce\', \'meta_box_nonce\' );
// Render the custom fields:
?>  
    <div>
        <input type="checkbox" id="page_title_off" name="page_title_off" <?php checked( $check, \'on\' ); ?> />
        <label for="page_title_off">Turn off page title</label>
    </div>
<?php } ?>
<?php
add_action( \'save_post\', \'cd_meta_box_save\' );
function cd_meta_box_save( $post_id )
{
    // Bail if we\'re doing an auto save
    if( defined( \'DOING_AUTOSAVE\' ) && DOING_AUTOSAVE ) return;
    // if our nonce isn\'t there, or we can\'t verify it, bail
    if( !isset( $_POST[\'meta_box_nonce\'] ) || !wp_verify_nonce( $_POST[\'meta_box_nonce\'], \'my_meta_box_nonce\' ) ) return;
    // if our current user can\'t edit this post, bail
    if( !current_user_can( \'edit_post\' ) ) return;
    // now we can actually save the data
    $allowed = array( 
        \'a\' => array( // on allow a tags
            \'href\' => array() // and those anchors can only have href attribute
        )
    );
    // Save
    if( isset( $_POST[\'page_title_off\'] ) )
    update_post_meta( $post_id, \'page_title_off\', $_POST[\'page_title_off\'] );

}
?>