wordpress怎么在常规设置里添加其他选项

/**
 * WordPress 添加额外选项字段到常规设置页面
 */
$new_general_setting = new new_general_setting();
class new_general_setting {
    function new_general_setting( ) {
        add_filter( 'admin_init' , array( &$this , 'register_fields' ) );
    }
    function register_fields() {
        register_setting( 'general', 'favorite_color', 'esc_attr' );
        add_settings_field('favorite_color', '<label for="favorite_color">'.__('最喜欢的颜色' ).'</label>' , array(&$this, 'fields_html') , 'general' );
    }
    function fields_html() {
        $value = get_option( 'favorite_color', '' );
        echo '<input type="text" id="favorite_color" name="favorite_color" value="' . $value . '" />';
    }
}

<?php echo get_option('favorite_color');?>