看一段简单的Flutter代码,直接复制到main.dart就可以

import 'package:flutter/material.dart';
import 'dart:ui';

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

class ImageViewPage extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text("Flutter Image"),
        ),
        body: new ListView(
          children: [assetsImage, networkImage],
        ),
      ),
    );
  }

  // assets图片
  Container assetsImage = new Container(
    child: new Image.asset(
      "assets/images/flutter_img.jpeg",
      width: window.physicalSize.width,
      height: 240.0,
      //类似于Android的scaleType 此处让图片尽可能小 以覆盖整个widget
      fit: BoxFit.cover,
    ),
  );

  // 网络图片
  Container networkImage = new Container(
      // 距离上一个组件的margin
      margin: EdgeInsets.all(10.0),
      child: new ClipRRect(
        // 圆角
        borderRadius: BorderRadius.circular(10.0),
        child: new Image.network(
          "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1554110093883&di=9db9b92f1e6ee0396b574a093cc987d6&imgtype=0&src=http%3A%2F%2Fn.sinaimg.cn%2Fsinacn20%2F151%2Fw2048h1303%2F20180429%2F37c0-fzvpatr1915813.jpg",
          width: window.physicalSize.width,
          height: 240.0,
          //类似于Android的scaleType 此处让图片尽可能小 以覆盖整个widget
          fit: BoxFit.cover,
        ),
      ));
}

效果

Simulator Screen Shot - iPhone Xʀ - 2019-09-05 at 16.18.21.png

Flutter 加载assets图片

1.lib 同级目录下新建一个assets文件夹
2.pubspec.yaml 配置

assets:
    - assets/images/flutter_img.jpeg

然后点击Packages get
以下代码就可以加载assets下的图片

// assets图片
  Container assetsImage = new Container(
    child: new Image.asset(
      "assets/images/flutter_img.jpeg",
      width: window.physicalSize.width,
      height: 240.0,
      fit: BoxFit.cover,
    ),
  );

Flutter 加载网络图片

child: new Image.network(
          "imageUrl",
          // 屏幕宽度
          width: window.physicalSize.width,
          height: 240.0,
          fit: BoxFit.cover,
),

设置图片圆角

new ClipRRect(
    borderRadius: BorderRadius.circular(6.0),
    child: new Image.network(
    )
),