我正在与woocommerce一起创建一个主题，其内容如下：

<ul>

  <li>
    <?php 
    if( is_user_logged_in() ){ 
    ?>
      <a href="<?php echo get_permalink( get_option( \'woocommerce_myaccount_page_id\' ) ); ?>" title="<?php _e( \'My Account\', \'woothemes\' ); ?>"><?php _e( \'My Account\', \'woothemes\' ); ?></a>
    <?php } else { ?>
      <a href="<?php echo get_permalink( get_option( \'woocommerce_myaccount_page_id\' ) ); ?>" title="<?php _e( \'Sign-in\', \'woothemes\' ); ?>"><?php _e( \'Sign-in\', \'woothemes\' ); ?></a>
    <?php 
    } 
    ?>
  </li>

  <li>
    <a href="<?php echo get_option( \'home\' ) . \'/\' . \'my-lists/\' ?>" title="My Wishlist">Wishlist</a>
  </li>

  <!--
  <li><a href="#" title="Email updates">Email Updates</a></li>
  -->
  <li> 
    <?php 
    global $woocommerce; 
    ?>
    <a id="header-ShoppingCart" class="cart-contents" href="<?php echo $woocommerce->cart->get_cart_url(); ?>" title="<?php _e( \'View your shopping cart\', \'woothemes\' ); ?>"><?php echo sprintf( _n( \'%d item\', \'My Bag (%d)\', $woocommerce->cart->cart_contents_count, \'woothemes\' ), $woocommerce->cart->cart_contents_count ); ?> - <span id="header-cartCount"><?php echo $woocommerce->cart->get_cart_total(); ?></span></a>
  </li>

</ul>

但是，如果woocommerce插件未激活，则会破坏网站。如何检查woocommerce插件是否已激活？

<?php
if ( class_exists( \'WooCommerce\' ) ) {
  // code that requires WooCommerce
} else {
  // you don\'t appear to have WooCommerce activated
}
?>

if ( in_array( \'woocommerce/woocommerce.php\', apply_filters( \'active_plugins\', get_option( \'active_plugins\' ) ) ) ) {
    echo \'WooCommerce is active.\';
} else {
    echo \'WooCommerce is not Active.\';
}

include_once( ABSPATH . \'wp-admin/includes/plugin.php\' );
if ( is_plugin_active( \'woocommerce/woocommerce.php\') ) {
  // Do what you want in case woocommerce is installed
}