Question

我有这个代码，我正在尝试使这个 gridview 可滚动，无论我做什么，它都不会滚动。我不断收到此渲染溢出错误。我试图将它包裹在 SingleChildScroll 视图和 Physics: ScrollPhysics() 的属性中，但没有任何效果。我只需要使这个 gridView 可滚动，而不是它下面的文本。我已经尝试了几种方法，但到目前为止没有任何方法适用于它。可能是我在这里做的一个愚蠢的错误，但无法弄清楚。 编辑：当我在脚手架的 body 标记之后设置 singleChildScrollView 时它工作正常，但当我将它应用到 GridView 时不起作用。

    class _CartGridViewState extends State<CartGridView> {
  @override
  Widget build(BuildContext context) {
    final User user = FirebaseAuth.instance.currentUser;
    double sum = 0;
    print(user);
    return StreamBuilder(
      stream: FirebaseFirestore.instance
          .collection('Users')
          .doc(user.uid)
          .collection('Cart')
          .snapshots(),
      builder: (BuildContext context, snapshot) {
        if (!snapshot.hasData) {
          return Center(
            child: CircularProgressIndicator(),
          );
        }
        var document = snapshot.data.docs;

        return Padding(
          padding: const EdgeInsets.all(10.0),
          child: SingleChildScrollView(
            physics: ScrollPhysics(),
            child: GridView.builder(
                physics: ScrollPhysics(),
                scrollDirection: Axis.vertical,
                primary: false,
                shrinkWrap: true,
                itemCount: document.length,
                gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                  crossAxisCount: 2,
                  childAspectRatio: MediaQuery.of(context).size.height / 800,
                ),
                itemBuilder: (context, index) {
                  if (document[index].data()["name"] == null) {
                    return Text('There are $index items in cart');
                  } else {
                    return Card(
                      child: GestureDetector(
                        onTap: () {
                          Navigator.push(
                            context,
                            MaterialPageRoute(
                                builder: (context) => CartView(
                                      document[index].data()["name"],
                                      document[index]
                                          .data()["price"]
                                          .toDouble(),
                                      document[index].data()["image"],
                                      index,
                                    )),
                          );
                        },
                        child: Stack(children: [
                          ListView(physics: ScrollPhysics(), children: [
                            Hero(
                              tag: 'tagImage$index',
                              child: Image.network(
                                "${document[index].data()["image"]}",
                                height: 150,
                              ),
                            ),
                            Center(
                                child: Text(
                                    "Price ${document[index].data()["price"]}")),

                         
                          ]),
                          DeleteCartItems(index),
                        ]),
                      ),
                    );
                  }
                }),
          ),
        );
      },
    );
    
  }
}

Answer 1

我们可以利用 Expanded widget 来获得可滚动的 GridView 请参考以下代码

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<String> images = [
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
    "https://images.unsplash.com/photo-1614961234425-dedd96e5e699?ixlib=rb-1.2.1&ixid=MXwxMjA3fDB8MHxleHBsb3JlLWZlZWR8M3x8fGVufDB8fHw%3D&auto=format&fit=crop&w=500&q=60",
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Padding(
        padding: EdgeInsets.symmetric(
          horizontal: 12.0,
        ),
        child: Expanded(
          child: GridView.builder(
            itemCount: images.length,
            shrinkWrap: true,
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 2,
                crossAxisSpacing: 8.0,
                mainAxisSpacing: 10.0),
            itemBuilder: (BuildContext context, int index) {
              return Image.network(images[index]);
            },
          ),
        ),
      ),
    );
  }
}

GridView.builder 不滚动

1 个答案: