plugin_dir_path（__FILE__）返回没有斜杠的URL

Question

我无法使用plugin_dir_path( __FILE__ )在wordpress中获取我的插件网址 该函数返回没有斜杠的URL。像下面一样

  

F：INSTALLEDXAMPPhtdocswordpresswp-contentpluginssubscribe /

    if ( !function_exists( 'add_action' ) ) {
    echo 'Hi there!  I\'m just a plugin, not much I can do when called directly.';
}

define( 'PLUGIN_DIR', plugin_dir_path( __FILE__ ) );


include_once(PLUGIN_DIR."/includes/admin/widget-class.php");
function enqueue_scripts(){
    wp_enqueue_style( 'bootstrap', 'https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css', array() ); //bootstrap CSS
    wp_enqueue_script( 'bootstrap', 'https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js', array('jquery'), null, true ); //bootstrap js

    wp_enqueue_script( 'sub_subscribe', PLUGIN_DIR.'js/subscribe.js', array('jquery'),null ,true );
// this is where I'm getting a the wrong path of the plugin
    $ajax_url = admin_url( 'admin-ajax.php' );



    // localize script
    wp_localize_script( 'sub_subscribe', 'ajax_url', $ajax_url );
}
add_action( 'wp_enqueue_scripts', 'enqueue_scripts' );

这是我得到的错误

  

（索引）：182 GET http://localhost/wordpressF:INSTALLEDXAMPPhtdocswordpresswp-contentpluginssubscribe/js/subscribe.js 403（禁止访问）