我是using this code here 用于重复CPT中的字段（是的，我知道ACF和其他一些），并尝试添加第三个字段。

该字段当前显示在元框中，并在前端输出。然而，在元框字段中（当它为空时），是一个

“未定义索引的通知：第235行上的角色…”（我将指出下面的哪一行），

前端写着

“注意：未定义索引：第29行的角色…”

在我的单个discog项目上。php文件。

我可以在后端更新和保存该字段，并在前端显示它，但我无法让这些通知消失，即使在网络上嗅探一下。

有没有关于如何解决这个问题的建议

    add_action(\'admin_init\', \'add_meta_boxes\', 1);
function add_meta_boxes() {
    add_meta_box( \'repeatable-fields\',
        \'Personnel Listing:\',
        \'awc_discog_meta_two\',
        \'discog-item\',
        \'normal\',
        \'high\');
}

function awc_discog_meta_two() {
    global $post;

    $repeatable_names = get_post_meta($post->ID, \'repeatable_names\', true);

    wp_nonce_field( \'repeatable_meta_box_nonce\', \'repeatable_meta_box_nonce\' );
?>
    <script type="text/javascript">
        //THE JS WORKS FINE
    </script>

    <table id="repeatable-fieldset-one" width="100%">
    <thead>
        <tr>
            <th width="2%"></th>
            <th width="30%">Name</th>
            <th width="20%">Role</th>
            <th width="40%">URL</th>
            <th width="2%"></th>
        </tr>
    </thead>
    <tbody>
    <?php

    if ( $repeatable_names ) :

        foreach ( $repeatable_names as $field ) {
?>
    <tr>
        <td><a class="button remove-row" href="#" title="Remove This Item">-</a></td>
        <td><input type="text" class="widefat" name="name[]" value="<?php if($field[\'name\'] != \'\') echo esc_attr( $field[\'name\'] ); ?>" placeholder="Charles Mingus"/></td>
//THE NEXT LINE IS LINE 235
        <td><input type="text" class="widefat" name="role[]" value="<?php if($field[\'role\'] != \'\') echo esc_attr( $field[\'role\'] ); ?>" placeholder="guitar/oud"/></td>
        <td><input type="text" class="widefat" name="url[]" value="<?php if ($field[\'url\'] != \'\') echo esc_attr( $field[\'url\'] ); ?>" placeholder="http://"/></td>
        <td><a class="sort">Sort</a></td>

    </tr>
    <?php
        }
    else :
        // show a blank one
?>
    <tr>
        <td><a class="button remove-row" href="#" title="Remove This Item">-</a></td>
        <td><input type="text" class="widefat" name="name[]" placeholder="Charles Mingus"/></td>
        <td><input type="text" class="widefat" name="role[]" placeholder="guitar/oud" /></td>
        <td><input type="text" class="widefat" name="url[]" placeholder="http://" /></td>
<td><a class="sort">Sort</a></td>

    </tr>
    <?php endif; ?>

    <!-- empty hidden one for jQuery -->
    <tr class="empty-row screen-reader-text">
        <td><a class="button remove-row" href="#">-</a></td>
        <td><input type="text" class="widefat" name="name[]" placeholder="Charles Mingus"/></td>
        <td><input type="text" class="widefat" name="role[]" placeholder="guitar/oud" /></td>
        <td><input type="text" class="widefat" name="url[]" placeholder="http://" /></td>
<td><a class="sort">Sort</a></td>

    </tr>
    </tbody>
    </table>

    <p><a id="add-row" class="button" href="#">Add another</a>
    <input type="submit" class="metabox_submit" value="Save" />
    </p>

    <?php
}

add_action(\'save_post\', \'repeatable_meta_box_save\');
function repeatable_meta_box_save($post_id) {
    if ( ! isset( $_POST[\'repeatable_meta_box_nonce\'] ) ||
        ! wp_verify_nonce( $_POST[\'repeatable_meta_box_nonce\'], \'repeatable_meta_box_nonce\' ) )
        return;

    if (defined(\'DOING_AUTOSAVE\') && DOING_AUTOSAVE)
        return;

    if (!current_user_can(\'edit_post\', $post_id))
        return;

    $old = get_post_meta($post_id, \'repeatable_names\', true);
    $new = array();


    $names = $_POST[\'name\'];
    $roles = $_POST[\'role\'];
    $urls = $_POST[\'url\'];


    $count = count( $names );

    for ( $i = 0; $i < $count; $i++ ) {

        if ( $roles[$i] != \'\' ) 
            $new[$i][\'role\'] = stripslashes( strip_tags( $roles[$i] ) );


        if ( $names[$i] != \'\' ) :
            $new[$i][\'name\'] = stripslashes( strip_tags( $names[$i] ) );



        if ( $urls[$i] == \'http://\' )
            $new[$i][\'url\'] = \'\';
        else
            $new[$i][\'url\'] = stripslashes( $urls[$i] ); // and however you want to sanitize
        endif;
    }

    if ( !empty( $new ) && $new != $old )
        update_post_meta( $post_id, \'repeatable_names\', $new );
    elseif ( empty($new) && $old )
        delete_post_meta( $post_id, \'repeatable_names\', $old );
}

<?php
$args = array( \'post_type\' => \'discog-item\', \'posts_per_page\' => -1 );
$loop = new WP_Query( $args );
$repeatable_names = get_post_meta($post->ID, \'repeatable_names\', true);
while ( $loop->have_posts() ) : $loop->the_post();
  the_title();
  echo \'<div class="entry-content">

  if (!empty($repeatable_names)) {

      echo \'<ul class="personnel">\';
      foreach ($repeatable_names as $field) { 

        $the_name = $field[\'name\'];
//THE NEXT LINE IS LINE 29
        $the_role = $field[\'role\'];
        $the_url = $field[\'url\'];

        echo \'<li>\';

        if (!empty($the_name)) {
            echo $the_name;
        }

        if (!empty($the_role)) {
            echo $the_role;
        }

        if (!empty($the_url)) {
            echo \'<a href="\' . $the_url . \'" target="_blank">Visit Website</a>\';
        }

        echo \'</li>\';
  }

  echo \'</ul>\';
} else {
    echo "Nothing to see here...";
}

  the_content();
  echo \'</div>\';
endwhile;
?>