将字段添加到 Woocommerce 注册表单并在管理编辑用户中

在 WooCommerce 中，我在帐户注册表单中添加了额外的字段：

// 1. ADD FIELDS
add_action( 'woocommerce_register_form_start', 'add_woo_account_registration_field' );
function add_woo_account_registration_field() {
    ?>

    <p class="form-row form-row-first">
    <label for="reg_billing_account_number"><?php _e( 'Ship to/ Account number', 'woocommerce' ); ?> <span class="required">*</span></label>
    <input type="text" class="input-text" name="billing_account_number" id="reg_billing_account_number" value="<?php if ( ! empty( $_POST['billing_account_number'] ) ) esc_attr_e( $_POST['billing_account_number'] ); ?>" />
    </p>

    <div class="clear"></div>

    <?php
}

// 2. VALIDATE FIELDS
add_filter( 'woocommerce_registration_errors', 'validate_woo_account_fields', 10 );
function validate_woo_account_fields( $errors, $username, $email ) {
    if ( isset( $_POST['billing_account_name'] ) && empty( $_POST['billing_account_number'] ) ) {
        $errors->add( 'billing_account_number_error', __( '<strong>Error</strong>: account number is required!', 'woocommerce' ) );
        $fields['billing_account_number']['maxlength'] = 6;
    }
    return $errors;
}

// 3. SAVE FIELDS
add_action( 'woocommerce_created_customer', 'save_woo_account_fields' );

function save_woo_account_fields( $customer_id ) {
    if ( isset( $_POST['billing_account_number'] ) ) {
        update_user_meta( $customer_id, 'billing_account_number', sanitize_text_field( $_POST['billing_account_number'] ) );
        update_user_meta( $customer_id, 'account_number', sanitize_text_field($_POST['billing_account_number']) );
    }
}

But 字段验证不起作用因为用户仍然可以在不填写的情况下进行注册。
我做错了什么？

此外，当客户注册时，我希望在管理员用户页面上看到此字段。

任何帮助表示赞赏。

以下将在客户注册中添加“计费帐号”字段作为必填字段（验证）并显示它：

• 在我的帐户 > 编辑帐户部分
• 在管理员用户编辑页面的计费字段部分

代码：

// Display a field in Registration / Edit account
add_action( 'woocommerce_register_form_start', 'display_account_registration_field' );
add_action( 'woocommerce_edit_account_form_start', 'display_account_registration_field' );
function display_account_registration_field() {
    $user  = wp_get_current_user();
    $value = isset($_POST['billing_account_number']) ? esc_attr($_POST['billing_account_number']) : $user->billing_account_number;
    ?>
    <p class="woocommerce-form-row woocommerce-form-row--wide form-row form-row-wide">
    <label for="reg_billing_account_number"><?php _e( 'Ship to/ Account number', 'woocommerce' ); ?> <span class="required">*</span></label>
    <input type="text" maxlength="6" class="input-text" name="billing_account_number" id="reg_billing_account_number" value="<?php echo $value ?>" />
    </p>
    <div class="clear"></div>
    <?php
}

// registration Field validation
add_filter( 'woocommerce_registration_errors', 'account_registration_field_validation', 10, 3 );
function account_registration_field_validation( $errors, $username, $email ) {
    if ( isset( $_POST['billing_account_number'] ) && empty( $_POST['billing_account_number'] ) ) {
        $errors->add( 'billing_account_number_error', __( '<strong>Error</strong>: account number is required!', 'woocommerce' ) );
    }
    return $errors;
}

// Save registration Field value
add_action( 'woocommerce_created_customer', 'save_account_registration_field' );
function save_account_registration_field( $customer_id ) {
    if ( isset( $_POST['billing_account_number'] ) ) {
        update_user_meta( $customer_id, 'billing_account_number', sanitize_text_field( $_POST['billing_account_number'] ) );
    }
}

// Save Field value in Edit account
add_action( 'woocommerce_save_account_details', 'save_my_account_billing_account_number', 10, 1 );
function save_my_account_billing_account_number( $user_id ) {
    if( isset( $_POST['billing_account_number'] ) )
        update_user_meta( $user_id, 'billing_account_number', sanitize_text_field( $_POST['billing_account_number'] ) );
}

// Display field in admin user billing fields section
add_filter( 'woocommerce_customer_meta_fields', 'admin_user_custom_billing_field', 10, 1 );
function admin_user_custom_billing_field( $args ) {
    $args['billing']['fields']['billing_account_number'] = array(
        'label'         => __( 'Ship to/ Account number', 'woocommerce' ),
        'description'   => '',
        'custom_attributes'   => array('maxlength' => 6),
    );
    return $args;
}

代码位于活动子主题（活动主题）的 function.php 文件中。经过测试并有效。