flutter_fooddelivery/lib/pages/order/components/categories.dart

import 'package:flutter/material.dart';
import 'package:fooddeliveryapp/constants.dart';

class Categories extends StatefulWidget {
  @override
  _CategoriesState createState() => _CategoriesState();
}

class _CategoriesState extends State<Categories> {
  List<String> categories = ["锅底", "荤菜", "素菜", "主食", "酒水", "调料"];

  int selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.symmetric(vertical: kDefaultPaddin),
      child: SizedBox(
        height: 35,
        child: ListView.builder(
            itemCount: categories.length,
            scrollDirection: Axis.horizontal,
            itemBuilder: (context, index) => buildCategory(index)),
      ),
    );
  }

  Widget buildCategory(int index) {
    return GestureDetector(
      onTap: () {
        setState(() {
          selectedIndex = index;
          print("[order页面]选择了第" + index.toString() + "个菜单页面");
        });
      },
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: kDefaultPaddin),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              categories[index],
              style: TextStyle(
                  fontWeight: FontWeight.bold,
                  color: selectedIndex == index ? kTextColor : kTextLightColor),
            ),
            Container(
              margin: EdgeInsets.only(top: kDefaultPaddin / 4),
              height: 2,
              width: 30,
              color: selectedIndex == index ? Colors.black : Colors.transparent,
            )
          ],
        ),
      ),
    );
  }
}