Flutter 中在单个屏幕上实现多个列表

今天，我将提供一个实际的示例，演示如何在单个页面上实现多个列表，这些列表可以水平排列、网格格式、垂直排列，甚至是这些常用布局的组合。

下面是要做的：

实现

让我们从创建一个包含产品所有属性的产品模型开始。

class Product {
  final String id;
  final String name;
  final double price;
  final String image;

  const Product({
    required this.id,
    required this.name,
    required this.price,
    required this.image,
  });

  factory Product.fromJson(Map json) {
    return Product(
      id: json['id'],
      name: json['name'],
      price: json['price'],
      image: json['image'],
    );
  }
}

现在，我们将设计我们的小部件以支持水平、垂直和网格视图。

创建一个名为 HorizontalRawWidget 的新窗口小部件类，定义水平列表的用户界面。

import 'package:flutter/material.dart';
import 'package:multiple_listview_example/models/product.dart';

class HorizontalRawWidget extends StatelessWidget {
  final Product product;

  const HorizontalRawWidget({Key? key, required this.product})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(
        left: 15,
      ),
      child: Container(
        width: 125,
        decoration: BoxDecoration(
            color: Colors.white, borderRadius: BorderRadius.circular(12)),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Padding(
              padding: const EdgeInsets.fromLTRB(5, 5, 5, 0),
              child: ClipRRect(
                borderRadius: BorderRadius.circular(12),
                child: Image.network(
                  product.image,
                  height: 130,
                  fit: BoxFit.contain,
                ),
              ),
            ),
            Expanded(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Expanded(
                      child: Text(product.name,
                          maxLines: 2,
                          overflow: TextOverflow.ellipsis,
                          style: const TextStyle(
                              color: Colors.black,
                              fontSize: 12,
                              fontWeight: FontWeight.bold)),
                    ),
                    Row(
                      crossAxisAlignment: CrossAxisAlignment.end,
                      children: [
                        Text("\$${product.price}",
                            style: const TextStyle(
                                color: Colors.black, fontSize: 12)),
                      ],
                    ),
                  ],
                ),
              ),
            )
          ],
        ),
      ),
    );
  }
}

设计一个名为 GridViewRawWidget 的小部件类，定义单个网格视图的用户界面。

import 'package:flutter/material.dart';
import 'package:multiple_listview_example/models/product.dart';

class GridViewRawWidget extends StatelessWidget {
  final Product product;

  const GridViewRawWidget({Key? key, required this.product}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(5),
      decoration: BoxDecoration(
          color: Colors.white, borderRadius: BorderRadius.circular(10)),
      child: Column(
        children: [
          AspectRatio(
            aspectRatio: 1,
            child: ClipRRect(
              borderRadius: BorderRadius.circular(10),
              child: Image.network(
                product.image,
                fit: BoxFit.fill,
              ),
            ),
          )
        ],
      ),
    );
  }
}

最后，让我们为垂直视图创建一个小部件类。

import 'package:flutter/material.dart';
import 'package:multiple_listview_example/models/product.dart';

class VerticalRawWidget extends StatelessWidget {
  final Product product;

  const VerticalRawWidget({Key? key, required this.product}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 15, vertical: 5),
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
      color: Colors.white,
      child: Row(
        children: [
          Image.network(
            product.image,
            width: 78,
            height: 88,
          ),
          const SizedBox(
            width: 15,
          ),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  product.name,
                  style: const TextStyle(fontSize: 12, color: Colors.black, fontWeight: FontWeight.bold),
                ),
                SizedBox(
                  height: 5,
                ),
                Text("\$${product.price}",
                    style: const TextStyle(color: Colors.black, fontSize: 12)),
              ],
            ),
          )
        ],
      ),
    );
  }
}

现在是时候把所有的小部件合并到一个屏幕中了，我们先创建一个名为“home_page.dart”的页面，在这个页面中，我们将使用一个横向的 ListView、纵向的 ListView 和 GridView。

import 'package:flutter/material.dart';
import 'package:multiple_listview_example/models/product.dart';
import 'package:multiple_listview_example/utils/product_helper.dart';
import 'package:multiple_listview_example/views/widgets/gridview_raw_widget.dart';
import 'package:multiple_listview_example/views/widgets/horizontal_raw_widget.dart';
import 'package:multiple_listview_example/views/widgets/title_widget.dart';
import 'package:multiple_listview_example/views/widgets/vertical_raw_widget.dart';

class HomePage extends StatelessWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    List products = ProductHelper.getProductList();
    return Scaffold(
      backgroundColor: const Color(0xFFF6F5FA),
      appBar: AppBar(
        centerTitle: true,
        title: const Text("Home"),
      ),
      body: SingleChildScrollView(
        child: Container(
          padding: const EdgeInsets.symmetric(vertical: 20),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              const TitleWidget(title: "Horizontal List"),
              const SizedBox(
                height: 10,
              ),
              SizedBox(
                height: 200,
                child: ListView.builder(
                    shrinkWrap: true,
                    scrollDirection: Axis.horizontal,
                    itemCount: products.length,
                    itemBuilder: (BuildContext context, int index) {
                      return HorizontalRawWidget(
                        product: products[index],
                      );
                    }),
              ),
              const SizedBox(
                height: 10,
              ),
              const TitleWidget(title: "Grid View"),
              Container(
                padding:
                    const EdgeInsets.symmetric(horizontal: 15, vertical: 10),
                child: GridView.builder(
                    gridDelegate:
                        const SliverGridDelegateWithFixedCrossAxisCount(
                            crossAxisCount: 2,
                            crossAxisSpacing: 13,
                            mainAxisSpacing: 13,
                            childAspectRatio: 1),
                    itemCount: products.length,
                    shrinkWrap: true,
                    physics: const NeverScrollableScrollPhysics(),
                    itemBuilder: (BuildContext context, int index) {
                      return GridViewRawWidget(
                        product: products[index],
                      );
                    }),
              ),
              const TitleWidget(title: "Vertical List"),
              ListView.builder(
                  itemCount: products.length,
                  shrinkWrap: true,
                  physics: const NeverScrollableScrollPhysics(),
                  itemBuilder: (BuildContext context, int index) {
                    return VerticalRawWidget(
                      product: products[index],
                    );
                  }),
            ],
          ),
        ),
      ),
    );
  }
}

我使用了一个 SingleChildScrollView widget 作为代码中的顶部根 widget，考虑到我整合了多个布局，如水平列表、网格视图和垂直列表，我将所有这些 widget 包装在一个 Column widget 中。

挑战在于如何处理多个滚动部件，因为在上述示例中有两个垂直滚动部件：一个网格视图和一个垂直列表视图。为了禁用单个部件的滚动行为， physics 属性被设置为 const NeverScrollableScrollPhysics()。取而代之的是，使用顶层根 SingleChildScrollView` 来启用整个内容的滚动。此外， SingleChildScrollView上的shrinkWrap属性被设置为true，以确保它能紧紧包裹其内容，只占用其子控件所需的空间。

Github 链接：https://github.com/tarunaronno005/flutter-multiple-listview