在woocommerce产品页面上保存多选自定义文件

// 添加自定义字段
function add_custom_file_field() {
    add_meta_box(
        'custom_file_field',
        '自定义文件',
        'render_custom_file_field',
        'product',
        'normal',
        'high'
    );
}
add_action('add_meta_boxes', 'add_custom_file_field');

// 渲染自定义字段
function render_custom_file_field($post) {
    // 获取已保存的文件信息
    $custom_files = get_post_meta($post->ID, 'custom_files', true);
    
    // 输出文件选择框
    echo '<label for="custom_files">选择文件：</label>';
    echo '<input type="file" name="custom_files[]" multiple>';
    
    // 输出已保存的文件列表
    if (!empty($custom_files)) {
        echo '<ul>';
        foreach ($custom_files as $file) {
            echo '<li><a href="' . $file['url'] . '">' . $file['name'] . '</a></li>';
        }
        echo '</ul>';
    }
}

// 保存自定义字段值
function save_custom_file_field($post_id) {
    if (isset($_FILES['custom_files'])) {
        $files = $_FILES['custom_files'];
        $file_urls = array();
        
        foreach ($files['name'] as $key => $name) {
            if ($files['error'][$key] === 0) {
                $upload_dir = wp_upload_dir();
                $file_name = sanitize_file_name($name);
                $file_path = $upload_dir['path'] . '/' . $file_name;
                
                if (move_uploaded_file($files['tmp_name'][$key], $file_path)) {
                    $file_urls[] = array(
                        'name' => $name,
                        'url' => $upload_dir['url'] . '/' . $file_name
                    );
                }
            }
        }
        
        if (!empty($file_urls)) {
            update_post_meta($post_id, 'custom_files', $file_urls);
        }
    }
}
add_action('save_post_product', 'save_custom_file_field');

// 获取自定义文件信息
$custom_files = get_post_meta(get_the_ID(), 'custom_files', true);

// 显示自定义文件列表
if (!empty($custom_files)) {
    echo '<ul>';
    foreach ($custom_files as $file) {
        echo '<li><a href="' . $file['url'] . '">' . $file['name'] . '</a></li>';
    }
    echo '</ul>';
}