向wordpress的Post“Publish”框添加自定义复选框

function add_custom_publish_checkbox() {
    add_meta_box(
        'custom_publish_checkbox',
        'Custom Checkbox',
        'render_custom_publish_checkbox',
        'post',
        'side',
        'high'
    );
}
add_action('add_meta_boxes', 'add_custom_publish_checkbox');

function render_custom_publish_checkbox($post) {
    wp_nonce_field(basename(__FILE__), 'custom_publish_checkbox_nonce');
    $value = get_post_meta($post->ID, '_custom_checkbox_value', true);
    echo '<label for="custom_checkbox">';
    echo '<input type="checkbox" id="custom_checkbox" name="custom_checkbox" value="1" ' . checked(1, $value, false) . '/>';
    echo ' Enable Feature';
    echo '</label>';
}

function save_custom_publish_checkbox($post_id) {
    if (!isset($_POST['custom_publish_checkbox_nonce'])) {
        return;
    }
    if (!wp_verify_nonce($_POST['custom_publish_checkbox_nonce'], basename(__FILE__))) {
        return;
    }
    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
        return;
    }
    if (!current_user_can('edit_post', $post_id)) {
        return;
    }
    if (isset($_POST['custom_checkbox'])) {
        update_post_meta($post_id, '_custom_checkbox_value', 1);
    } else {
        delete_post_meta($post_id, '_custom_checkbox_value');
    }
}
add_action('save_post', 'save_custom_publish_checkbox');

$custom_checkbox_value = get_post_meta(get_the_ID(), '_custom_checkbox_value', true);
if ($custom_checkbox_value == 1) {
    // 复选框被选中，执行相应操作
}