有没有什么方法可以实现一个多输入字段，该字段可以容纳用户想要输入的任意多个短语？

是的，有&mdash；您可以添加input 用户将在其中输入数字的字段，该数字是他/她要添加的额外短语的数量。

但我会使用JavaScript/jQuery解决方案，其中我们使用类似的可重复字段脚本this. 试试demo 如果您在使用脚本/代码时需要帮助，请告诉我。

下面是我如何用您的phrases 字段：

首先，注册脚本文件并将其排队。例如：

add_action( \'admin_menu\', \'my_add_admin_menu\' );
function my_add_admin_menu() {
    // I used `add_options_page()`, but you can use similar function. The point
    // is, we\'d need the `$hook_suffix` variable.
    $hook_suffix = add_options_page( \'WPSE 309235\', \'WPSE 309235\', \'manage_options\', \'wpse-309235\', \'my_options_page\' );

    // Registers and enqueues our repeatable field script. You shouldn\'t "hotlink"
    // to CodePen. Instead, save the file to my-repeatable-field.js and upload it
    // to your site, and then link to that file.
    add_action( \'load-\' . $hook_suffix, function(){
        wp_register_script( \'my-repeatable-field\', \'https://codepen.io/anon/pen/vaJaGZ.js\', [ \'jquery\' ], \'20180727\' );
        wp_enqueue_script( \'my-repeatable-field\' );
    } );
}

function my_options_page() {
  echo \'<div class="wrap">\';
    echo \'<h2>\'.esc_html( get_admin_page_title() ).\'</h2>\';
    echo \'<h3>Setup / Settings</h3>\';
    //settings_errors(); // In my case, this isn\'t necessary.
    echo \'<form action="options.php" method="post">\';
      settings_fields("my_group");
      echo \'<table class="form-table repeatable-field">\';
        $phrases_arr = my_options( \'phrases\' );
        $count = count( $phrases_arr );

        echo \'<tr valign="top"><th colspan="2">Data Input</th></tr>\';
        // Displays 3 initial rows.
        $rows = max( $count, 3 );
        for ( $i = 0, $j = 1; $i < $rows; $i++, $j++ ) {
            $phrase_str = isset( $phrases_arr[ $i ] ) ? $phrases_arr[ $i ] : \'\';
            echo \'<tr valign="top" class="repeatable-field-row">\' .
                \'<th scope="row">Phrase [<span class="repeatable-field-number">\' . $j . \'</span>]</th>\' .
                \'<td><input name="my_options[phrases][]" value="\' . esc_attr( $phrase_str ) . \'" size="32" type="text" class="repeatable-field-input">\' .
                    \'<span class="repeatable-field-buttons"></span></td>\' .
            \'</tr>\';
        }

        $phrases_url = my_options( \'phrases_url\' );
        echo \'<tr valign="top">\' .
            \'<th>Phrases URL (*Non-repeatable* Field)</th>\' .
            \'<td><input type="text" name="my_options[phrases_url]" value="\' . esc_attr( $phrases_url ) . \'" class="regular-text" placeholder="URL"></td>\' .
        \'</tr>\';
      echo \'</table>\';
      submit_button();
    echo \'</form>\';
  echo \'</div>\';
}

function my_options( $key = null ) {
    $options = wp_parse_args( get_option( \'my_options\' ), [
        \'phrases\'     => [],
        \'phrases_url\' => \'\',
    ] );

    // Returns a single option.
    if ( $key ) {
        return isset( $options[ $key ] ) ? $options[ $key ] : null;
    }

    // Returns all the options.
    return $options;
}

function my_validate($input){
  $phrases_arr = [];

  foreach ($input[\'phrases\'] as $phrase) {
    if ( $phrase = esc_html( $phrase ) ) {
      $phrases_arr[] = $phrase;
    }
  }

  $input[\'phrases\'] = $phrases_arr;

  return $input;
}