Flutter如何处理固定尺寸的盒子内的图像？

Question

我是Flutter的新手，我喜欢它，但是我对建筑布局不满意。

我正在开发一个包含Cards ListView的应用程序。每张卡都在一个容器内，并包含一张图像（高度和宽度固定）和一个文本。

我无法将图像正确放置在卡内。我希望图像覆盖盒子的宽度。谢谢。

这是代码：

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final title = 'MyApp';

    return MaterialApp(
      title: title,
      home: Scaffold(
        appBar: AppBar(
          title: Text(title),
        ),
        body: ListView(
          children: <Widget>[
              Container(
                    margin:EdgeInsets.all(8.0),
                    child: Card(
                        shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(8.0))),
                        child: InkWell(
                           onTap: () => print("ciao"),     
                           child: Column(
                                children: <Widget>[
                                    ClipRRect(
                                      borderRadius: BorderRadius.only(
                                        topLeft: Radius.circular(8.0),
                                        topRight: Radius.circular(8.0),
                                      ),
                                      child: Image.asset(
                                        'img/britannia.jpg',
                                        width: 300,
                                        height: 150,
                                        fit:BoxFit.fill  

                                      ),
                                    ),
                                    ListTile(
                                      title: Text('Pub 1'),
                                      subtitle: Text('Location 1'),
                                    ),
                                ],
                           ),
                        ),
                    ),
              ),
          ],
        ),
      ),
    );
  }
} 

Answer 1

这对我有用

Image.network(imageUrl, fit: BoxFit.fitWidth,),

Answer 2

我不知道如何......但这确实有效地在容器中保持固定大小的图像只需在容器中添加对齐

    Container(
      height: double.infinity,
      alignment: Alignment.center, // This is needed
      child: Image.asset(
        Constants.ASSETS_IMAGES + "logo.png",
        fit: BoxFit.contain,
        width: 300,
      ),
    );

Answer 3

 Image.asset(
                  'assets/images/desert.jpg',
                  height: 150,
                  width: MediaQuery.of(context).size.width,
                  fit:BoxFit.cover

              )

Answer 4

child: Container(
              alignment: Alignment.center,// use aligment
              child: Image.asset(
                'assets/images/call.png',
                height: 45,
                width: 45,
                fit: BoxFit.cover,
              ),
            ),

如果你想要边框，请使用这个

            Center(
          child: Container(
            margin: EdgeInsets.only(top: 75),
            width: 120,
            height: 120,
            alignment: Alignment.center,
            child: Image.asset(
              "assets/images/call.png",
              fit: BoxFit.cover,
              height: 45,
              width: 45,
            ),
            decoration: new BoxDecoration(
              color: Colors.white,
              borderRadius: new BorderRadius.all(new Radius.circular(120)),
              border: new Border.all(
                color: Colors.blue,
                width: 4.0,
              ),
            ),
          ),
        )

Answer 5

您需要添加- crossAxisAlignment: CrossAxisAlignment.stretch,在Column让孩子们占用的横向空间。

工作代码：

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final title = 'MyApp';

return MaterialApp(
  title: title,
  home: Scaffold(
    appBar: AppBar(
      title: Text(title),
    ),
    body: ListView(
      children: <Widget>[
        Container(
          margin:EdgeInsets.all(8.0),
          child: Card(
            shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(8.0))),
            child: InkWell(
              onTap: () => print("ciao"),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,  // add this
                children: <Widget>[
                  ClipRRect(
                    borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(8.0),
                      topRight: Radius.circular(8.0),
                    ),
                    child: Image.network(
                        'https://placeimg.com/640/480/any',
                       // width: 300,
                        height: 150,
                        fit:BoxFit.fill

                    ),
                  ),
                  ListTile(
                    title: Text('Pub 1'),
                    subtitle: Text('Location 1'),
                  ),
                ],
              ),
            ),
          ),
        ),
        Container(
          margin:EdgeInsets.all(8.0),
          child: Card(
            shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(8.0))),
            child: InkWell(
              onTap: () => print("ciao"),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>[
                  ClipRRect(
                    borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(8.0),
                      topRight: Radius.circular(8.0),
                    ),
                    child: Image.network(
                        'https://placeimg.com/640/480/any',
                        // width: 300,
                        height: 150,
                        fit:BoxFit.fill

                    ),
                  ),
                  ListTile(
                    title: Text('Pub 1'),
                    subtitle: Text('Location 1'),
                  ),
                ],
              ),
            ),
          ),
        ),
        Container(
          margin:EdgeInsets.all(8.0),
          child: Card(
            shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(8.0))),
            child: InkWell(
              onTap: () => print("ciao"),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>[
                  ClipRRect(
                    borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(8.0),
                      topRight: Radius.circular(8.0),
                    ),
                    child: Image.network(
                        'https://placeimg.com/640/480/any',
                        // width: 300,
                        height: 150,
                        fit:BoxFit.fill

                    ),
                  ),
                  ListTile(
                    title: Text('Pub 1'),
                    subtitle: Text('Location 1'),
                  ),
                ],
              ),
            ),
          ),
        ),
      ],
    ),
      ),
    );
  }
}

输出：

Answer 6

将图像小部件放在容器内，并为容器提供对齐中心，并为图像提供特定的宽高。

return Container(
      alignment: Alignment.center,// use aligment
      color: Color.fromRGBO(0, 96, 91, 1.0),
      child: Image.asset('assets/images/splash_logo.png',
        height: 150,
        width: 150,
      fit: BoxFit.cover),
    );

Answer 7

如果可以使用 fit 属性，我会让这个非常清晰的备忘单（章节 fit 属性）详细说明所有内容： https: //medium.com/jlouage/flutter-boxdecoration-cheat-sheet-72cedaa1ba20