我正在开发我的第一个插件，当我尝试访问wp admin时，wordpress显示以下错误：致命错误：未捕获错误：调用中未定义的函数settings\\u fields（）/插件/wtdomcheck/admin/html/settings。菲律宾比索：25

插件文件wtdomcheck。php

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define( \'WTDOMCHECK_PLUGIN_DIR\',    plugin_dir_path( __FILE__ ) );
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if ( is_admin() ) {
  require_once( \'admin/wtdomcheck_admin.php\' );
} else {
  require_once( \'public/wtdomcheck_front.php\' );
}
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插件文件wtdomcheck\\u admin。php

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require_once WTDOMCHECK_PLUGIN_DIR.\'admin/class/class-admin.php\';

if ( class_exists(admin) ) {

    $wtdomadmin = new admin();
    $wtdomadmin->register();

}
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插件文件类管理。php

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require_once \'api.php\';


class admin 
{
    public $pluginName;

    public $settings;

    public $pages = array();

    public $subpages = array();


    function __construct() 
    {
        $this->pluginName = plugin_basename( __FILE__ );

        $this->settings = new ApiWpadmin();

        $this->pages = [
            [
                \'page_title\' => \'WT Domain Check\', 
                \'menu_title\' => \'WTDomCheck\', 
                \'capability\' => \'manage_options\', 
                \'menu_slug\'  => \'wtdomaincheck\', 
                \'callback\'   => $this->LoadSettingTemplate(), 
                \'icon_url\'   => \'dashicons-store\', 
                \'position\'   => 117
            ]
        ];

        $this->subpages = [
            /*[
                \'parent_slug\'=> \'wtdomaincheck\',
                \'page_title\' => \'Settings\', 
                \'menu_title\' => \'Settings\', 
                \'capability\' => \'manage_options\', 
                \'menu_slug\'  => \'settings\',
                \'callback\'   => function() { echo \'<h1>Taxonomies Manager</h1>\'; },
            ]*/
        ];

        add_action( \'add_meta_boxes\', array( $this, \'LoadMetabox\') ); 

        add_action(\'edit_form_after_title\', array( $this, \'DelAllMetaboxes\') );

    }



    //
    // PARAM
    // Register all the actions and filters for the Admin area
    //
    public function register() 
    {
        //Call the concatenated API method to contruct the menu, and submenu
        $this->settings->AddPages( $this->pages )->WithSubPage( \'Settings\' )->AddSubPages( $this->subpages )->register();

        add_action(\'admin_init\', array($this, \'SaveSettings\') );

        add_filter( \'plugin_action_links_\'.WTDOMCHECK_PLUGIN_NAME, array($this->settings, \'AddCustomLinks\') );

        add_action("manage_posts_custom_column",  array( $this, \'EditColumns\') );

        add_filter("manage_edit-wt_whoisservers_columns", array( $this, \'FilterColumns\') );
    }


    //
    // PARAM
    // Loads the template that shows the settings page
    //
    public function LoadSettingTemplate()
    {
        include_once WTDOMCHECK_PLUGIN_DIR.\'admin/html/settings.php\';
    }

插件文件设置。php

<?php

//require_once \'/www/lr-webstower.com.ar/htdocs/wp-load.php\';

//array($field_type, $echo_string, $id, $rows)
$fields = array(
    array(\'checkbox\',\'Field 1\',\'fieldname1\',\'1\'),
    array(\'checkbox\',\'Field 2\',\'fieldname2\',\'1\'),
    array(\'textarea\',\'Field 3\',\'fieldname3\',\'3\'),
    array(\'textarea\',\'Field 4\',\'fieldname4\',\'3\'),
    array(\'textarea\',\'Field 5\',\'fieldname5\',\'3\'),
    array(\'text\',\'Field 6\',\'fieldname6\',\'1\'),
    array(\'text\',\'Field 7\',\'fieldname7\',\'1\'),
    array(\'text\',\'Field 8\',\'fieldname8\',\'1\'),
    array(\'text\',\'Field 9\',\'fieldname9\',\'1\'),
    array(\'text\',\'Field 10\',\'fieldname10\',\'1\'),
    array(\'echo\',\'Message 1\',\'\',\'1\')
);

?>
<div class="wrap">
    <h2><?php _e(\'WTDomCheck Setup\', \'wtdomcheck\') ?></h2>
    <form method="post" action="options.php">

        <?php settings_fields( \'wtdomcheck-settings\' ); ?>

        <div id="poststuff">
            <div class="postbox">
            <h3> <?php _e(\'Result Settings\', \'wtdomcheck\') ?></h3>
                <div class="inside">
                    <table class="form-table">

$this->pages = [
            [
                \'page_title\' => \'WT Domain Check\', 
                \'menu_title\' => \'WTDomCheck\', 
                \'capability\' => \'manage_options\', 
                \'menu_slug\'  => \'wtdomaincheck\', 
                \'callback\'   => $this->LoadSettingTemplate(), 
                \'icon_url\'   => \'dashicons-store\', 
                \'position\'   => 117
            ]
        ];

\'callback\'   => array($this,\'LoadSettingTemplate\'),