在电子邮件通知上显示自定义结帐帐单字段

In WooCommerce, I want to add some custom fields on checkout which will be displayed under the billing section on the e-mail confirmation. My custom fields and their values, shown on the checkout form and on the order page on back end (WooCommerce -> Orders). So far everything works great.

The problem is that the e-mail that i receive does not contain the custom fields and their values.

Code shown below:

    add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );
    function custom_override_checkout_fields( $fields ) {
        $fields['billing']['billing_field_testing'] = array(
            'label'     => __('TestingField', 'woocommerce'),
            'placeholder'   => _x('TestingField', 'placeholder', 'woocommerce'),
            'required'  => false,
            'class'     => array('form-row-wide'),
            'clear'     => true
             );
        return $fields;
    }

    add_action( 'woocommerce_admin_order_data_after_billing_address', 'my_custom_checkout_field_display_admin_order_meta', 10, 1 );
    function my_custom_checkout_field_display_admin_order_meta($order)
    {
        echo '<p><strong>'.__('TestingField').':</strong> ' . get_post_meta( $order->id, '_billing_field_testing', true ) . '</p>';
    }

Please help.

Thanks in advance

Updated: To display your custom checkout field in email notifications below the billing address, use this function hooked in woocommerce_email_customer_details action hook with a priority above 20:

add_action('woocommerce_email_customer_details','add_custom_checkout_field_to_emails_notifications', 25, 4 );
function add_custom_checkout_field_to_emails_notifications( $order, $sent_to_admin, $plain_text, $email ) {

    $output = '';
    $billing_field_testing = get_post_meta( $order->id, '_billing_field_testing', true );

    if ( !empty($billing_field_testing) )
        $output .= '<div><strong>' . __( "Some text:", "woocommerce" ) . '</strong> <span class="text">' . $billing_field_testing . '</span></div>';

    echo $output;
}

The Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

This code is tested and works.

You will need to customize email templates under woocommerce/templates/emails/ to your-theme/woocommerce/emails/

Youc an override whatever template you want end add custom field there.

Alternatively, you can also add them using hook from following code:

add_filter( 'woocommerce_email_order_meta_fields', 'custom_woocommerce_email_order_meta_fields', 10, 3 );

function custom_woocommerce_email_order_meta_fields( $fields, $sent_to_admin, $order ) {
    $fields['meta_key'] = array(
        'label' => __( 'Label' ),
        'value' => get_post_meta( $order->id, 'meta_key', true ),
    );
    return $fields;
}