flutter控件設置背景圖

效果圖

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(MaterialApp(
    debugShowCheckedModeBanner: false,
    home: MyApp(),
  ));
  if (Platform.isAndroid) {
    SystemUiOverlayStyle systemUiOverlayStyle =
        SystemUiOverlayStyle(statusBarColor: Colors.transparent);
    SystemChrome.setSystemUIOverlayStyle(systemUiOverlayStyle);
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Expanded(
          child: Stack(
            children: <Widget>[
              Container(
                decoration: BoxDecoration(
                    image: DecorationImage(
                        image: AssetImage('assets/images/tzd.jpg'),
                        fit: BoxFit.fill)),
              ),
              Container(
                width: MediaQuery.of(context).size.width,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: <Widget>[
                    SizedBox(
                      width: 100.0,
                      height: 50.0,
                      child: RaisedButton(
                        onPressed: () {},
                        child: Text('點我'),
                      ),
                    ),
                    SizedBox(
                      width: 200.0,
                      height: 50.0,
                      child: RaisedButton(
                        onPressed: () {},
                        child: Text('點我'),
                      ),
                    ),
                  ],
                ),
              )
            ],
          ),
          flex: 1,
        ),
        Expanded(
          child: Container(
            decoration: BoxDecoration(
                image: DecorationImage(
                    image: NetworkImage(
                        'https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1591269784591&di=de025a187c52c667e911415dc467de51&imgtype=0&src=http%3A%2F%2Ffiles.bbs.tl.changyou.com%2Fdata%2Fattachment%2Fforum%2F201507%2F20%2F161520i5zwef38nnnh1c5e.jpeg'),
                    fit: BoxFit.fill)),
          ),
          flex: 1,
        ),
      ],
    );
  }
}