如何获得 WooCommerce 运输方式的成本和设置?

I'm trying to get all shipping methods, with their rates and title. But when i use WC()->shipping->get_shipping_methods() it will only return empty rates array, and empty title string. Here is a dump:

     array (size=3)
  'flat_rate' => 
    object(WC_Shipping_Flat_Rate)[1861]
      protected 'fee_cost' => string '' (length=0)
      public 'supports' => 
        array (size=3)
          0 => string 'shipping-zones' (length=14)
          1 => string 'instance-settings' (length=17)
          2 => string 'instance-settings-modal' (length=23)
      public 'id' => string 'flat_rate' (length=9)
      public 'method_title' => string 'Flat rate' (length=9)
      public 'method_description' => string 'Lets you charge a fixed rate for shipping.' (length=42)
      public 'enabled' => string 'yes' (length=3)
      public 'title' => string '' (length=0)
      public 'rates' => 
        array (size=0)
          empty
      public 'tax_status' => string '' (length=0)
      public 'fee' => null
      public 'minimum_fee' => null
      public 'instance_id' => int 0
      public 'instance_form_fields' => 
        array (size=3)
          'title' => 
            array (size=5)
              ...
          'tax_status' => 
            array (size=5)
              ...
          'cost' => 
            array (size=7)
              ...
      public 'instance_settings' => 
        array (size=0)
          empty
      public 'availability' => null
      public 'countries' => 
        array (size=0)
          empty
      public 'plugin_id' => string 'woocommerce_' (length=12)
      public 'errors' => 
        array (size=0)
          empty
      public 'settings' => 
        array (size=4)
          'title' => string '' (length=0)
          'tax_status' => string '' (length=0)
          'cost' => string '' (length=0)
          'type' => string 'class' (length=5)
      public 'form_fields' => 
        array (size=0)
          empty
      protected 'data' => 
        array (size=0)
          empty
      public 'cost' => string '' (length=0)
      public 'type' => string 'class' (length=5)

我试图用谷歌搜索这个问题，但没有任何帮助.有谁知道可能是什么问题?

// Get all your existing shipping zones IDS
$zone_ids = array_keys( array('') + WC_Shipping_Zones::get_zones() );

// Loop through shipping Zones IDs
foreach ( $zone_ids as $zone_id ) 
{
    // Get the shipping Zone object
    $shipping_zone = new WC_Shipping_Zone($zone_id);

    // Get all shipping method values for the shipping zone
    $shipping_methods = $shipping_zone->get_shipping_methods( true, 'values' );

    // Loop through each shipping methods set for the current shipping zone
    foreach ( $shipping_methods as $instance_id => $shipping_method ) 
    {
        // The dump of protected data from the current shipping method
        var_dump($shipping_method);
    }
}